ct  N  7> 


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Digitized  by  the  Internet  Archive 
in  2018  with  funding  from 
Getty  Research  Institute 


https://archive.org/details/metalworkershandOObran 


THE 


METAL  WORKER’S  HANDY-BOOK 

OF 

RECEIPTS  AND  PROCESSES. 


BEING  A  COLLECTION  OF  CHEMICAL  FORMULAS  AND  PRAC¬ 
TICAL  MANIPULATIONS  FOR  THE  WORKING  OF  ALL 
THE  METALS  AND  ALLOYS;  INCLUDING  THE  DEC¬ 
ORATION  AND  BEAUTIFYING  OF  ARTICLES  MANU¬ 
FACTURED  THEREFROM,  AS  WELL  AS 
THEIR  PRESERVATION. 


Edited,  from  Various  Sources,  bv 

WILLIAM  T.  BRANNT, 

EDITOR  OF  “THE  TECHNO-CHEMICAL  RECEIPT  BOOK”  AND  “THE  METALLIC  ALLOYS.” 


ILLUSTRATED  BY  SIXTY-THREE  ENGRAVINGS. 


PHILADELPHIA : 

HENRY  CAREY  BAIRD  &  CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS  AND  IMPORTERS, 

810  Walnut  Street. 

LONDON : 

SAMPSON  LOW,  MARSTON,  SEARLE  &  RIVINGTON,  Limited, 
ST.  dunstan’s  house,  fetter  lane,  fleet  street. 

1890. 


Copyright  by  Henry  Carey  Baird  &  Co.,  1890. 


PRINTED  AT 

COLLINS  PRINTING  HOUSE, 

PHILADELPHIA,  U.  8.  A. 


THE  GETTY  CENTER 

I  IPDARV 


PREFACE. 


SINCE  chemistry  has  become  the  hand-maid  of  the  industries, 
it  is  next  to  impossible  to  keep  secret  for  any  length  of  time 
the  composition  of  a  specialty,  the  analytical  chemist  taking  care 
that  it  soon  becomes  common  property.  But  the  results  of  his 
labors  being  of  necessity  scattered  through  the  various  technical 
journals,  not  always  readily  accessible,  the  advantages  derived 
therefrom  by  the  practical  workman  are  very  problematical,  unless 
he  can  procure  the  information  wanted  without  the  expense  of 
the  time  and  labor  required  for  examining  the  very  numerous 
original  sources  of  such  information. 

To  collect  such  flotsam  and  jetsam  of  the  technical  journals, 
domestic  and  foreign,  has  been  the  design  in  preparing  the  matter 
for  the  present  volume ;  and  thus  to  furnish  to  the  metal-worker, 
in  the  form  of  a  handy- book,  receipts  and  processes  of  practical 
application,  which  would  otherwise  be  in  great  measure  overlooked 
or  entirely  lost.  In  the  treatment  of  the  different  subjects  they 
have,  as  far  as  practicable,  been  divested  of  all  mere  technicalities, 
also  omitting  that  which  was  not  properly  relevant. 

At  the  present  time  the  public  is  accustomed  to  the  consideration 
of  useful  facts,  set  forth  in  the  briefest  terms,  and,  bearing  this  in 
mind,  in  many  cases  a  single  article  has  been  made  to  embrace 
data  from  a  number  of  different  sources.  With  the  aid  of  a  liberal 
supply  of  foreign  and  domestic  books  and  journals  bearing  on  the 

(iff) 


iv 


PREFACE. 


various  subjects,  which  have  been  furnished  by  the  enterprising 
publishers,  the  editor  trusts  that  not  much  of  interest  or  importance 
has  been  omitted.  In  consulting  innumerable  volumes  and  journals 
every  care  has  been  taken  to  select  the  best  receipts  and  processes, 
and  the  editor  is  confident  that  every  metal-worker,  no  matter  in 
what  branch  of  the  industry  he  may  be  engaged,  will  here  find 
something  of  use  and  benefit  to  himself. 

In  regard  to  the  practical  application  of  the  receipts,  the  observ¬ 
ance  of  the  following  rules  is  recommended  :  i.  Be  careful  to  use 
the  exact  proportions  prescribed.  2.  Always  first  experiment  with 
small  quantities.  3.  Should  the  first  attempt  prove  unsuccessful, 
do  not  condemn  the  receipt,  but  make  another  trial,  as  the  fault 
can  generally  be  traced  to  a  mistake  in  the  manipulation  or  an 
error  in  the  quantities. 

The  alphabetical  arrangement  of  related  subjects  adopted  and  a 
very  copious  table  of  contents,  as  well  as  index,  will  render  refer¬ 
ence  to  any  subject  or  special  receipt  prompt  and  easy. 

WM.  T.  BRANNT. 


Philadelphia,  September  10,  1890. 


CONTENTS. 


I.— Chemical  Relations  of  the  Metals. 

Number  of  metals  distinguished  by  the  chemist;  Principal  metals  and 
alloys  used  by  the  practical  metal-worker;  Advantage  of  a  knowledge  of 
the  chemical  properties  of  metals  to  the  metal-worker  .  .  .  -33 

Behavior  of  metals  towards  oxygen ;  Phenomena  in  the  oxidation  of  potas¬ 
sium  .............  34 

Definitions  of  oxidation  and  oxide;  Fusibility  of  zinc;  Combustion  of 
metals ;  Formation  of  cupric  and  cuprous  oxides ;  Definition  of  super¬ 
oxides  and  protoxide  ..........  35 

Definition  of  sub-oxide;  Base  and  noble  metals;  Combinations  of  the 
metals  with  chlorine ;  Preparation  of  chlorine ;  Precautions  in  using 
chlorine  ;  Manner  of  collecting  chlorine  in  a  bottle  .  .  .  -36 

Combustion  of  Dutch  gold  in  chlorine  ;  Solution  of  gold  in  chlorine  water; 
Definition  of  metallic  chlorides ;  Preparation  of  metallic  chlorides ;  Defi¬ 
nitions  of  hydrogen  and  oxyhydrogen  gas  ......  37 

Chloride  of  zinc  ;  Metals  which  do  not  dissolve  in  hydrochloric  acid  .  .  38 

Aqua  regia  and  its  action  on  gold  and  platinum ;  Combinations  of  silver 
and  lead  with  chlorine ;  Combinations  of  the  metals  with  sulphur ;  Con¬ 
version  of  copper  into  cuprous  sulphide ;  Mosaic  gold  ;  Combinations  of 
iron  with  sulphur  ...........  39 

Conversion  of  iron  into  ferrous  sulphide ;  Iron  pyrites ;  Laws  of  combina¬ 
tion  of  the  elements ;  Table  of  the  most  important  elements  with  their 
symbols  and  atomic  weights  .........  40 

Definition  of  atomic  or  indivisible  weights;  Manner  of  expressing  chemical 
combinations ;  Metallic  salts  .........  41 

Definition  of  bases  and  acids ;  Preparation  of  litmus  tincture  and  litmus- 
paper  ;  Definition  of  salts ;  Cupric  sulphate  or  blue  vitriol ;  Acetate  of 
lead  or  sugar  of  lead  ;  Formation  of  metallic  salts  .  .  .  .  .42 

Combinations  of  metallic  oxides  with  acids ;  Definition  and  formation  of 
haloid  salts ;  Chromate  of  lead  or  chrome  yellow ;  Precipitates  with  sul¬ 
phuretted  hydrogen  . . .  43 

Apparatus  for  preparing  sulphuretted  hydrogen,  illustrated  and  described  ; 
Characteristics  of  precipitates  obtained  with  sulphuretted  hydrogen  .  44 

(v) 


vi 


CONTENTS. 


II. — The  Most  Important  Metallic  Preparations,  and  the  Chemicals 


used  in  the  Metal  Industry. 

Iron  preparations;  Ferrous  sulphate  (copperas,  green  vitriol);  Ammonio- 
ferrous  sulphate ;  Ferrous  chloride  ;  Ferric  chloride  .  .  .  -45 

Sesquioxide  of  iron,  colcothar  or  rouge ;  Potassium-ferrocyanide  (yellow 
prussiate  of  potash) ;  Potassium  ferricyanide  (red  prussiate  of  potash) ; 
Ferric  sulphate;  Preparations  of  cobalt  and  nickel ;  Cobaltous  chloride  .  46 

Cobaltous  nitrate;  Cobaltous  oxide;  Nickel  chloride;  Nickel  sulphate; 
Nickel  nitrate  ;  Nickel  hydrate  ;  Copper  preparations  ;  Copper  powder  ; 
Cupric  sulphate  (sulphate  of  copper,  blue  vitriol)  .  .  .  .  -47 

Cupro-diammonium  sulphate ;  Copper  nitrate ;  Cupric  chloride ;  Copper 
nitrate;  Cupric  chloride  ;  Copper  carbonate  ;  Acetate  of  copper ;  Neutral 
acetate  of  copper  ...........  48 


Basic  acetate  of  copper  or  verdigris;  German  and  French  verdigris; 
Cyanide  of  copper ;  Cupric  and  cuprous  oxides;  Preparations  of  lead,  tin 
and  bismuth ;  Acetate  of  lead  (sugar  of  lead)  ;  Lead  carbonate  (white 


lead) ;  Lead  chloride  ..........  49 

Lead  sulphate  ;  Lead  chromate  (chrome  yellow)  ;  Stannous  chloride  (pro¬ 
tochloride  of  tin,  tin-salt);  Stannic  sulphide;  Mosaic  gold;  Bismuth 
nitrate  .............  50 

Preparations  of  zinc,  antimony  and  arsenic ;  Chloride  of  zinc  ;  Zinc  sulphate 
(white  vitriol)  ;  Zinc  oxide  ;  Iron  black  ;  Antimony  trichloride  (butter  of 
antimony);  Tartar  emetic  ;  White  arsenic  or  arsenious  acid  .  .  -51 

Schweinfurt  green  ;  Preparations  of  mercury  and  silver ;  Mercurous  sul¬ 
phate  ;  Mercuric  nitrate  ;  Mercurous  nitrate  ;  Mercuric  chloride  or  cor¬ 
rosive  sublimate  ;  Nitrate  of  silver  (silver  nitrate,  lunar  caustic)  .  .  52 

Chloride  of  silver  (argentic  chloride,  horn  silver)  ;  Argentic  oxide ;  Silver 
carbonate ;  Cyanide  of  silver  (prussiate  or  hydrocyanate  of  silver) ; 
Silver  sulphate  ;  Silver  sulphide  ;  Silver  hyposulphite  .  .  .  -  S3 

Preparations  of  gold  and  platinum  ;  Chloride  of  gold  (auric  chloride)  ; 
Aurous  chloride  ;  Cyanide  of  gold  (prussiate  or  hydrocyanate  of  gold)  ; 

Gold  salt  (Gozzy’s  gold  salt)  .........  54 

Purple  of  Cassius;  Platinic  chloride  (chloride  of  platinum,  tetra-chloride 
of  platinum) ;  Ammonio-chloride  of  platinum;  Spongy  platinum  .  .  55 

Acids ;  Sulphuric  acid  (oil  of  vitriol)  ;  Fuming  sulphuric  acid  or  Nord- 
hausen  sulphuric  acid  ..........  56 

Table  of  percentage  of  anhydrous  sulphuric  acid  at  different  degrees  B 6 ; 
Nitric  acid  (aqua  fortis)  .........  57 

Table  of  percentage  of  anhydrous  nitric  acid  at  different  degrees  Be ; 
Hydrochloric  acid  ...........  58 

Table  of  percentage  of  gaseous  hydrochloric  acid  at  different  degrees  Be  ; 
Aqua  regia  (nitro-muriatic  acid)  ........  59 


CONTENTS. 


vii 

Chromic  acid;  Acetic  acid;  Tartaric  acid ;  Boric  or  boracic  acid  .  .  60 

Oxalic  acid  (salt  of  sorrel);  Prussic  acid  (hydrocyanic  acid);  Various 
chemicals  and  substances  used  in  the  metal  industry ;  Ammonia  (spirits 

of  hartshorn)  ;  Ammonium  phosphate . 6l 

Ammonium  sulphide  (sulphydrate,  or  hydrosulphate  of  ammonia)  ;  Benzine 
(benzole,  light  oil  from  coal  tar) ;  Borax  (sodium  biborate) ;  Calcium, 
potassium  and  sodium  sulphides;  Caoutchouc  (India  rubber,  gum 

elastic) . 62 

Vulcanized  rubber ;  Carbon  bisulphide ;  Emery ;  Graphite  (plumbago, 

black  lead) ;  Gutta-percha . 63 

Magnesia  (calcined) ;  Potassium  bicarbonate ;  Potassium  cyanide  (white 
prussiate  of  potash) ;  Potassium  hydroxide  (caustic  potash)  ;  Potassium 
nitrate  (saltpetre) ;  Sodium  bicarbonate ;  Sodium  hydroxide  (caustic 


soda) ;  Sodium  phosphate  (tribasic  phosphate  of  soda)  .  .  .  .64 

Sodium  pyrophosphate  (bibasic  phosphate  of  soda) ;  Sulphur ;  Tartar 
(potassium  bitartrate)  ..........  65 


III. — Directions  for  the  Determination  of  the  Constituents  of 
Metallic  Alloys,  Impurities  of  the  Technically  Most  Important 


Metals,  Etc. 

Manner  of  dissolving  metals ;  Characteristics  that  indicate  the  presence  of 

various  metals  in  the  solution . 66 

Manner  of  testing  for  mercury  ;  Determination  of  magnesium  ;  Determina¬ 
tion  of  nickel  and  cobalt  .........  67 

Determination  of  iron,  chromium,  manganese,  zinc,  alumina,  chloride  of 
silver,  chloride  of  lead  and  subchloride  of  mercury  .  .  .  .68 

Determination  of  gold,  platinum,  antimony,  tin,  bismuth,  copper,  cadmium 
and  arsenic  ............  69 

Marsh’s  apparatus  for  the  detection  of  arsenic,  illustrated  and  described ;  To 
distinguish  genuine  from  spurious  gold  .......  70 

To  test  gold  ware;  To  recognize  light  gilding  upon  metallic  articles  .  .  71 

To  recognize  light  silvering;  Test-water  for  silver  .  .  .  .  •  72 

To  distinguish  tin-foil  from  lead-foil ;  To  test  mercury  as  to  its  purity  ;  To 
test  tin  and  soft  solders ;  To  detect  lead  in  tin ;  To  test  brass  .  .  73 

To  test  white  metals,  copper  and  nickel;  To  test  acids;  To  detect  alloys  in 

gilding . 74 

To  test  enamel  for  lead;  Ready  distinction  of  cast-iron,  steel  and  wrought- 
iron;  Method  for  ascertaining  the  quality  of  iron  and  steel  .  .  -75 

Examination  of  burnt  iron  .........  76 

Resistance  of  a  few  metals  and  alloys  to  calcium  hydrate ;  How  to  tell  a 
hand-  from  a  machine-cut  file  ........  77 


CONTENTS. 


viii 


IV. — Alloys  and  Amalgams. 

Alloys  ;  Definition  of  an  amalgam  ;  Characteristics  and  properties  of  alloys ; 
Fusion  of  alloys;  Specific  gravity  of  alloys  ......  79 

Dr.  Ure’s  rule  for  calculating  the  specific  gravity  of  alloys;  Table  of  alloys 
whose  density  is  greater  or  less  than  the  mean  of  their  constituents ; 
Tenacity  of  alloys  ...........  80 

Preparation  of  alloys  ;  Rules  for  fusing  the  metals  .  .  .  .  .81 

The  fusing  points  of  the  principal  metals  and  other  elements  employed  in 
alloys;  Alloys  of  bismuth  and  cadmium  ......  82 

Alloys  of  copper  and  tin;  Bronze;  Definition  of  bronze  and  of  white 
metals  .............  83 

Ordnance  or  gun  metal ;  Table  showing  the  composition  of  ordnance  bronze 
of  various  times  and  different  countries  .......  84 

Steel  bronze  or  Uchatius  bronze ;  Bell-metal ;  Chinese  tam-tams  or  gongs  .  85 

Table  showing  the  composition  of  some  bell-metals;  Bell-metal  for  small 
bells ;  Japanese  bell-metal ;  Small  clock-bells,  table-bells,  sleigh-bells, 

etc . 86 

Silver  bell-metal ;  Machine  bronze  ;  Red  brass  and  white  brass  .  .  87 

Table  of  metals  for  bearings,  etc.  ........  88 

Locomotive  brass  castings ;  Brasses  for  side  rods  .  .  .  .  .89 


Brasses  for  driving  boxes ;  Bells ;  Castings  subjected  to  steam  pressure ; 
Pumps  and  pump  chambers;  Piston  packing  rings ;  Approved  composi¬ 
tions  for  bearings  of  rapidly  running  machines ;  Bearing  metals  for  loco¬ 
motives  ;  Babbitt’s  anti-attrition  metal  .......  90 

Fenton’s  alloy  for  axle-boxes  for  locomotives  and  wagons ;  Dewrance’s 
patent  bearing  for  locomotives ;  Alloy  for  anti-friction  brasses ;  Hoyle’s 


patent  alloy  for  pivot  bearings  ;  Phosphor  bronze  ;  Phosphide  of  copper ; 

Phosphide  of  tin  .  .  .  . . 91 

Various  sorts  of  phosphor  bronze ;  Silicon  bronze ;  Silicon  brass  ;  Statuary 
bronze  .............  92 

Table  of  alloys  of  different  colors  suitable  for  statuary  bronze;  Table  show¬ 
ing  the  compositions  of  a  few  celebrated  statues  .  .  .  .  -93 

Best  bronze  for  statues  according  to  D’Arcet;  Bronze  for  gilding;  Bronze 
for  small  castings;  Bronze  which  can  be  rolled ;  Chinese  bronzes ;  Delta 
metal  .............  94 

Gold  bronze ;  Japanese  bronze  ;  Malleable  bronze . 95 

Old  Peruvian  bronze  ;  Ormolu ;  Silveroid ;  Speculum  metal  .  .  .96 

Alloys  of  copper  and  zinc ;  Brass  and  similar  alloys  .  .  .  .  *97 

Color  of  copper-zinc  alloys ;  Table  of  the  composition  of  copper-zinc  alloys; 
Tombac  (red  brass)  and  similar  alloys  .......  98 

Table  of  the  composition  of  brass  and  similar  alloys . 99 

Alloys  of  copper  with  silver  and  gold  ;  Color  of  gold  alloys  .  .  .  100 


CONTENTS. 


ix 

Proportion  of  various  metals  in  gold  alloys  used  by  jewellers ;  Argent-Ruolz  ioi 
Gray  silver  (Japanese  silver) ;  Tiers  argent  (one:third  silver)  ;  Imitat'on 
silver  alloys ;  Alloy  for  spoons ;  Alloy  resembling  silver ;  Delalot’s  alloy ; 
Mousset’s  silver  alloy  ;  Warne’s  metal  .......  102 

White  alloy  closely  resembling  silver ;  Aluminium  alloys ;  Aluminium 
brasses  ;  Cowles  Bros.’  series  of  tests  of  aluminium  brass  .  .  .  103 

Aluminium  bronze  .  .  .  .  .  .  .  .  .  .  .104 

Directions  for  preparing  aluminium  bronzes  ......  105 

Ferro-aluminium  ...........  106 

Various  aliminium  alloys;  Alloy  for  dental  plates . 107 

Alloy  resembling  German  silver;  Alloy  resembling  silver;  Bourbonne’s 
aluminium  alloy;  Lechesne ;  Minargent;  Neogen  ....  10S 
Niirnberg  gold;  Britannia  metal  and  similar  alloys;  Table  of  composition 
of  several  varieties  of  Britannia  metal;  Ashberry  metal  ....  109 
Biddery  metal ;  Minofor  metal ;  Manganese  alloys;  Cupro-manganese  .  no 
Red  brass;  White  metal;  Ferro-manganese  ;  Manganese  silver;  Man¬ 
ganese  steel ;  Hadfield’s  manganese  steel  .  .  .  .  ...  in 

Nickel  alloys;  Nickel  and  copper;  Nickel  coins  of  the  United  States, 
Belgium  and  Brazil;  Nickel,  copper  and  zinc  alloys;  Table  of  the  com¬ 
position  of  various  kinds  of  German  silver  .  .  .  .  .  .112 

Alfenide,  Argiroide  and  allied  alloys  '.  .  .  .  .  .  113 

Albata  metal ;  Alfenide;  British  plate  metal;  Metal  for  spoons,  forks,  etc. ; 
White  alloy  resisting  the  action  of  vegetable  acids ;  White  argentan ; 
Alloys  of  nickel  and  steel  .  .  .  .  .  .  .  .  .114 

Type  metal ;  Table  of  alloys  suitable  for  casting  type  .  .  .  .115 

Ehrliardt’s  type  metal;  Music  plates  ;  Various  alloys ;  Acid-proof  bronze  ; 
Alloy  for  casting  small  articles;  Alloy  for  moulds  for  pressed  glass; 
Alloy  of  copper  and  antimony  .  .  .  .  .  .  .  .116 

Alloys  for  calico-printing  rollers;  Alloys  for  small  patterns  in  foundries; 

Birmingham  platinum  ;  Calin;  Cooper’s  alloy  for  steel  pens  ;  Dysiot  .  1 17 
Fahlun  or  tin  brilliants;  Gold  and  palladium  alloys;  Gold-like  alloy;  Iron 
alloy  .  .  .  .  .  .  .  .  .  .  .  .  .118 

Lemarquand’s  non-oxidizable  alloy ;  Lutecine  or  Paris  metal ;  Malleable 
brass ;  Marley’s  non-oxidizable  alloy  ;  New  alloys  ;  Alloy  for  the  manu¬ 
facture  of  jewelry  . 1 19 

New  imitations  of  gold  and  silver  .  .  .  .  .  .  .  .120 

New  method  of  preparing  alloys  ;  Non-magnetic  alloys  for  watches  .  .121 

Non-oxidizable  alloy;  Platinoid;  Platinum  bronze;  Shakdo  ;  Sideraphtite  ; 

Soft  alloy  for  coating  metals,  etc.  .  .  .  .  .  .  .  .122 

Amalgams;  Amalgam  of  Lipowitz’s  metal ;  Copper  amalgam  .  .  .123 

Gold  amalgam  .  .  .  .  .  .  .  .  .  .  .  .124 

Iron  amalgam  ;  Silver  amalgam ;  Tin  amalgam  .....  125 


X 


CONTENTS. 


Zinc  amalgam  .  .  .  .  . . .  .126 

V. — Annealing,  Hardening,  Tempering. 

Annealing  of  hard  and  other  iron  castings  .  .  .  .  .  .126 

To  make  steel  so  soft  that  it  can  be  worked  like  copper;  New 
way  of  annealing  steel;  Two  ways  of  annealing  steel;  Annealing  of 
bronze  .  .  .  .  .  .  .  .  .  .  .  .  .127 

To  harden  copper ;  To  case-harden  wrought-iron  .....  128 

To  case-harden  axie  arms ;  To  harden  cast-iron  ;  To  harden  cast-iron  in  a 
simple  manner  ...........  131 

To  quickly  and  thoroughly  harden  soft  iron  ;  To  harden  wrought-iron  parts 
of  machines  ............  132 

To  harden  steel  by  pressure;  To  harden  steel  in  petroleum;  To  harden 
steel  so  that  the  exterior  is  hard,  and  the  interior  soft  ....  133 

To  harden  small  drills ;  Hardening  water  for  steel ;  Fluids  for  hardening 
steel  articles  .  .  .  .  .  .  .  .  .  .  .  .134 

Hardening  compound  for  steel ;  Hardening  mixture,  patented  by  J.  Robb 
of  Dundee,  Forfarshire ;  To  avoid  cracks,  curving  and  warping  in  harden¬ 
ing  steel;  How  to  harden  thin  steel  plates  ......  135 

Hardening  of  steel  according  to  Newton  and  Ames ;  To  harden  steel  in 
sealing-wax  .  .  .  .  .  .  .  .  .  .  .  .136 

To  harden  springs  and  saws  .........  137 

To  harden  files  and  other  steel  instruments ;  To  harden  steel  instru¬ 
ments  .............  139 

To  harden  tools ;  Hardening  gun-barrels  according  to  Neunert  .  .  .  140 

To  harden  the  bores  of  musket-barrels ;  Adam  Schaefer’s  fluid  for  hardening 
steel ;  To  harden  copper  .........  141 

To  harden  zinc ;  Hardening  compound  ;  New  case-hardening  compound  ; 

Agents  for  hardening,  improving  and  welding  steel  .  .  .  .142 

Tempering  colors  of  steel  ..........  143 

Alloys  for  baths  used  in  tempering  and  heating  steel  articles ;  Effect  of 
temperature  on  steel  .  .  .  .  .  .  .  .  .  .  144 

To  temper  steel  by  electricity ;  To  temper  mining  picks;  To  temper  taps 
and  dies  ............  145 

Improvements  in  tempering  and  hardening  steel  and  iron  ....  146 

To  temper  brass  ;  To  temper  magnets  .......  147 

VI. — Bronzing  and  Coloring. 

Methods  of  bronzing  metals ;  Preparation  of  varnish  for  bronzing ;  Gold 
bronze ;  Silver  bronze  .....•••••  I4S 
Copper-bronze;  Red  bronze;  Green  bronze;  French  bronze  .  .  .  149 


CONTENTS.  xi 

Blue  bronze . I5° 

Brown  bronze ;  Bronzing  by  dipping  in  melted  bronze ;  Bronze  liquid ; 
Cheap  bronze  ;  To  bronze  small  brass  articles ;  Bronzing  process  used  in 

the  Paris  mint . ISI 

To  bronze  copper ;  To  bronze  copper  bluish-gray ;  Green  bronze  for 

brass . 152 

To  bronze  articles  of  copper  and  brass ;  Brown  fire-proof  bronze  upon  copper 

and  brass;  Green  bronzing . 1 53 

Bronzing  of  cast-iron;  Gold  bronze  of  great  lustre  on  iron;  To  bronze  cast- 

iron;  Bronze-like  surface  on  iron  or  steel . 154 

To  give  ground  steel  objects  the  appearance  of  gold  or  good  bronze  ;  To 

bronze  tin;  To  bronze  zinc . 155 

To  color  silvered  cast-zinc  articles ;  To  bronze  electrotypes  green,  brown, 
black;  To  bronze  medals  .  .  .  .  .  .  .  .  -156 

Graham’s  bronzing  liquids ;  For  brass  (by  simple  immersion)  .  .  .157 

For  copper  (by  simple  immersion)  ;  For  zinc  (by  simple  immersion)  .  .  158 

Rockline’s  method  of  bronzing ;  Walker’s  chemical  bronze  ;  Bronze  pow¬ 
ders  .  .  .  .  .  .  .  .  .  .  •  .  .  159 

Table  of  the  composition  of  alloys  for  some  colors  of  bronze  powders ; 

English  bronze  powders ;  Brocade  bronze  powder . 160 

Copper  bronze  powder;  Genuine  gold  bronze;  Aurum  musivum  (Mosaic 
gold)  .............  161 

Brownish-gold  bronze  powders;  Genuine  silver  bronze  powder;  Imitation 
silver  bronze  powder;  Argentum  musivum  ......  162 

Iron  black;  Metallochromy ;  To  color  articles  of  brass  ;  Preparation  of  the 
lead  solution  for  coloring  brass  .  .  .  .  .  .  .  .163 

Preparation  of  the  iron  solution  for  coloring  metals;  Preparation  of  the 
objects  to  be  colored;  Weil’s  process  of  producing  iridescent  copper  pre¬ 
cipitates  on  iron  ...........  164 

Approved  coatings  for  metals :  Black  or  colored  coat ;  Golden  yellow  to 
brown  coat ;  Black  coat  .  .  .  .  .  .  .  .  .165 

Beautiful  steel-gray;  New  process  of  producing  a  gold-colored  coating  upon 
small  metallic  articles  .  .  .  .  .  .  .  .  .  .166 

Colored  coatings  for  metals  .  .  .  ,  ,  ,  .  .  .167 

Coloring  of  copper;  Brown  color  upon  copper;  Red-brown  color  upon 

copper . . 168 

To  color  copper  blue-black ;  Preparation  of  cuivre  fumt ;  Steel-gray  upon 
copper  ;  To  color  copper  dark  steel-gray ;  Various  colors  upon  massive 

copper . 169 

Black  upon  copper  ;  Dead-black  on  copper ;  To  brown  copper;  Browning 
liquid  for  copper  .  .  ,  .  .  .  .  .  .  .  *170 

Imitation  of  genuine  patina  .........  1 7 1 


XU 


CONTENTS. 


Another  method  of  imitating  genuine  patina;  Coloring  of  brass  and  bronzes ; 

Lustrous  black  on  brass;  Steel-gray  on  brass  .  .  .  .  .  1 73 

Gray  color  with  a  bluish  tint  upon  brass ;  Straw  color  to  brown  through 
golden-yellow  and  tombac  color  on  brass ;  Color  resembling  gold  on 
brass;  Brown  color  called  bronze  Barbedienne  on  brass  .  .  .174 

Bronze  Barbedienne  on  massive  brass ;  To  color  brass  violet  and  corn¬ 
flower  blue  ;  Ebermayer’s  method  of  coloring  brass  .  .  .  .  1 75 

To  brighten  and  color  brass  .  .  .  .  .  .  .  .  .176 

Antimony  colors  on  brass ;  Dead -black  on  brass  instruments  .  .  .  177 

Deep  black-blue  stain  on  brass ;  Lustrous  gold  or  green  on  brass  .  .178 

Gold  and  orange  stains  for  brass;  Beautiful  silver  color  on  brass ;  New 
bronze  color  upon  brass  and  copper ;  To  color  copper  and  brass  .  .  1 79 

To  whiten  brass  and  copper;  To  blacken  small  iron  articles  in  bulk  .  .  180 

Lustrous  black  on  iron  ;  Brown-black  coating  with  bronze  lustre  on  iron ; 

To  give  iron  a  silver-like  appearance  with  high  lustre  .  •  .  .  181 

To  color  iron  and  steel  blue  ;  To  color  iron  and  steel  gray  ;  Thierault’s 
process  for  coloring  wrought-iron  and  steel  .  .  .  .  .  .182 

To  blue  small  articles  of  sheet-steel ;  To  blue  small  articles  of  iron  and 
steel  so  as  to  leave  portions  of  them  bright ;  Coloring  of  gold  .  .  183 

Bronze-like  patina  upon  tin  ;  Sepia-brown  on  tin  and  its  alloys  .  .  .184 

Coloring  zinc ;  Gray  coating  on  zinc  .  .......  185 

Green  coating  on  zinc  ;  Bronze  color  on  zinc  ;  Copper-red  on  zinc  .  .  186 

Red-brownish  color  on  zinc ;  Yellow-brown  shades  on  zinc ;  To  brown  gun- 
barrels  .  .  .  .  .  .  .  .  .  .  .  .  .187 

Another  method  of  browning  gun-barrels ;  To  blacken  damasked  gun- 
barrels;  To  brown  medals  and  coins  .......  188 

VII. — Casting  and  Founding. 

Properties  necessary  to  render  a  metal  suitable  for  casting ;  Shrinking  of 

metals  in  casting  . . .  189 

Table  showing  the  contraction  of  metals  in  casting  .....  191 

Easy  rule  to  find  approximate  weight  of  castings ;  Weight  of  castings ; 
Moulding  sand  for  castings  of  ingot  iron ;  To  prevent  the  baking  of 
moulding  sand  ...........  192 

Moulding  and  moulds  ..........  193 

Foundry  flasks  illustrated  and  described  . . .  196 

To  mould  lace,  etc.,  in  cast-iron  ........  200 

Cores  in  heavy  castings ;  Core  for  difficult  castings  .....  261 

Casting  without  core,  illustrated  and  described  ......  202 

Casting  brass-nuts  on  screws  .........  203 

Casting  on  to  other  metals  . . .  204 

Ornamenting  wrought-iron  by  burning  on  ......  205 


CONTENTS. 


xiii 


To  repair  castings  by  burning  on  ;  To  fill  up  holes  in  castings  .  .  .  206 

Bell  founding  ............  207 

Casting  aluminium  bronze  .........  209 

Thomas  D.  West  on  casting  aluminium  bronze  and  other  strong  metals  .  211 
To  cast  lead-pipe  free  from  flaws  ........  213 

Dense  and  flexible  copper  castings;  Wroughtiron  (or  Mitis)  castings  .  214 

Analyses  of  Mitis  metal . 215 

Casting  stereo-plates  by  the  paper  process  ;  Another  stereotype  process  .  217 
Manufacture  of  chilled  wheels  .  .  .  .  .  .  .  .  .219 

Casting  of  zinc  ............  223 

Apparatus  for  casting  metal  illustrated  and  described  .....  224 

Preparation  of  chills  for  casting  metal ;  Painting  and  varnishing  patterns  .  225 
Black-leading  of  patterns  ..........  226 

Varieties  of  wood  most  suitable  for  patterns;  To  preserve  iron  patterns 
from  rusting;  To  mend  patterns  ........  227 

Glue  for  pattern-makers ;  Improved  method  of  treating  steel  for  casting  .  228 

VIII. — Cements. 

Iron  cements  or  rust  joints . 228 

Iron  cement  which  stands  red  heat;  Cement  for  uniting  iron  surfaces  and 
filling  in  joints;  Cement  for  blowing  engines,  blast  pipes,  hot-blast  stoves, 
etc . 229 


Chenot’s  iron  cement;  Cement  for  gas  retorts  and  for  connecting  of  parts  of 
iron  exposed  to  heat ;  Cement  for  smearing  over  joints  of  iron  water  reser¬ 
voirs;  For  cementing  joints  or  cracks  in  iron  stoves;  For  air-tight  oven 
doors ;  For  fastening  iron  rods,  cramps,  hooks,  etc.,  especially  in  stone  230 
Cement  for  iron ;  To  cement  iron  to  iron ;  Cement  for  fastening  iron 
articles  in  stone;  Cement  for  repairing  defective  places  in  castings; 


Cement  for  iron  stoves ;  Cement  for  mending  iron  pots  and  pans  .  .  231 

Cement  for  making  joints;  Grouvelle’s  oil  cement;  Stephenson’s  oil 

cement ;  Serbat’s  mastic . 232 

Marteaux  and  Robert’s  cement;  Diamond  cement;  Glycerin  cement  for 

iron  ;  Fire-proof  and  water-proof  cements . 233 

Cement  for  electrical  or  chemical  apparatus ;  Acid-proof  cement ;  To 


cement  thin  metal-sheets ;  To  unite  glass  and  brass;  To  fasten  metallic 
mountings  upon  glass,  porcelain,  etc. ;  Cement  for  fastening  the  metal 
parts  upon  glass  lamps ;  To  cement  metal  plates  on  to  wooden  boxes  ;  To 

cement  iron  to  wood  or  stone  ;  To  fasten  metals  on  wood  .  .  .  234 

Cement  for  fastening  metal  upon  glass ;  Cements  for  fastening  metal  letters 
upon  glass,  marble,  wood,  etc. ;  To  cement  glass  into  metal  .  .  .  235 

Cement  for  fastening  brass  to  glass ;  To  fasten  leather  upon  iron  .  .  236 

To  fasten  paper  labels  to  iron ;  Cements  for  fastening  labels  on  polished 


XIV 


CONTENTS. 


nickel ;  To  cement  forks  and  knives  in  their  handles  ;  To  secure  forks 
and  knives  in  silver  handles  ;  To  cement  with  copper  amalgam;  Cements 
for  parts  of  machines  ..........  237 

Cement  for  steam  pipes;  For  parts  of  copper  and  brass;  For  pipe  conduits 
not  exposed  to  heat ;  For  packing  stuffing-boxes  and  pistons  of  engines  ; 

To  make  a  permanent  and  durable  joint  ......  238 

Schiefer’s  packing  rings  for  man-holes  and  flanges;  Colored  cement  for 
repairing  zinc  ornaments  .........  239 

Evans’s  metallic  cement;  Cement  for  luting  crucible  lids;  Cements  for 
water  pipes  ;  Cement  for  joining  cast-iron  water  pipes  (for  use  on  a  large 
scale) ;  Bismuth  cement  for  cementing  the  glass  parts  on  petroleum 
lamps;  Armenian  or  jeweller’s  cement  .......  240 


IX. — Cleansing,  Grinding,  Pickling,  Polishing. 

Cleansing  metals  with  the  sand  blast ;  Sand  blast  illustrated  and  described  241 


Cleansing  of  metals  by  means  of  acid  with  the  use  of  a  galvanic  current  .  242 
Scouring  and  polishing  of  knitting  needles;  To  scour  and  polish  needles  .  243 
To  cleanse  guns  with  petroleum  ........  244 

Cleansing  of  coins,  medals  and  articles  of  silver;  To  cleanse  golden-bronze  ; 

To  cleanse  bronze  fixtures;  To  cleanse  silvered  dial  plates  .  .  .  245 

To  cleanse  chandeliers  and  gas  fixtures;  To  cleanse  small  screws;  To  free 
iron  from  ingrained  rust;  To  remove  rust  from  polished  steel  articles;  To 
extract  rust  from  steel  ..........  246 

To  remove  rust  from  nickel-plated  articles;  To  freshen  up  nickel  watch 
movements ;  Grinding  ..........  247 

Rules  for  the  use  of  emery  wheels  ........  248 

Emery  wire ;  Emery  sticks  .........  249 

To  cleanse  emery  which  has  been  used;  Pickling  or  dipping  of  metallic 
objects ;  Pickle  for  cast-iron  or  wrought-iron  articles  ....  250 

Purpose  of  pickling  copper,  brass,  tombac,  and  bronze  .  .  .  *251 

English  process  of  pickling  brass  ........  252 

Method  usually  pursued  in  the  United  States  for  cleaning  brass  parts  ;  Pick¬ 
ling  of  German  silver;  To  pickle  zinc  .......  253 

To  give  a  brilliant  appearance  to  tombac,  brass  and  copper;  To  polish 
metals  .............  254 

Polishing  by  means  of  wheels;  Polishing  agents  or  polishing  powders; 
Lime;  Vienna  lime  ;  Ferric  oxide  .......  255 

Caput  mortuum,  crocus,  colcothar,  jeweller’s  red  or  rouge  ;  Tripoli  .  .  256 

Tin-putty;  Chalk;  Polishing  files  ;  Polishing  stock  ;  Buff  wheels;  Rough¬ 
ing  wheel;  Medium  wheel;  Fine  wheel  ......  257 

Tumbling  drum  or  box  illustrated  and  described . 258 


CONTENTS.  xv 

Polishing  with  the  burnisher  or  burnishing  stone  .....  259 
Most  common  forms  of  burnishing  tools  illustrated  and  described  .  .  260 

Burnishing  cutlery . 262 

To  burnish  silver ;  Scratch-brushing ;  How  to  make  a  hand  scratch-brush  .  263 

Hand  scratch-brushes  illustrated  and  described . 264 

Fluids  used  in  scratch-brushing  ;  Methods  of  scratch-brushing  .  .  .  265 

Scratch-brush  lathe  and  circular  scratch-brushes  illustrated  and  described  .  266 
Repairing  and  keeping  in  order  hand  scratch-brushes  ....  267 

Polishing  of  the  separate  metals :  Iron  and  steel ;  Copper,  brass,  German 
silver  and  tombac;  Gold;  Silver  and  plated  ware;  Dead  lustre  on 
articles  of  gold  and  silver  ;  Tin  articles  .......  268 

Polishing  of  antimony  and  lead  alloys ;  Polishing  of  zinc  ;  Polishing  agents ; 

Parisian  polishing  powder ;  Emery  cloth . 269 

Polishing  rags ;  Belgian  polishing  powder ;  Agents  for  cleansing  iron  and 
steel  objects;  For  soft  metals  (tin  and  Britannia  wares);  For  cleansing  silver¬ 
ware  ;  For  cleansing  silver  ornaments ;  Polishing  powders  for  silver  .  270 
English  silver  soap ;  Rose-color  English  silver  soap ;  Polishing  balls  for 
silver;  Polishing  paste  for  silver  .  .  .  .  .  .  .  .271 

Polishing  powder  for  gold-workers ;  Polishing  powder  for  gold  articles ; 
Polishing  paste  for  brass;  To  cleanse  brass  articles;  To  cleanse  old 
brass;  Polishing  soaps  ..........  272 

Polishing  water  ...........  273 

Polishing  (Putz)  pomades ;  Polishing  cartridges  (Putzpatronen)  ;  Polish 
for  pressed  articles  of  brass ;  Rouge  for  polishing  metals  .  .  .  274 

To  polish  steel ;  To  polish  steel  objects  .......  275 

Lustreless  surface  on  steel ;  To  polish  and  color  copper;  To  cleanse  dirty 
polishing  leather . 276 


X. — Decorating,  Enamelling,  Engraving,  Etching. 


Bronces  incrust£s  (incrustations) . 277 

Marie  Tessin  du  Motay’s  process  of  incrusting;  Corvin’s  Niello  .  .  278 

Damaskeening ;  Imitation  of  Damascus  steel  ......  279 

Damascus  gun-barrels ;  Turkish  damask  illustrated  and  described  .  .  280 

Barnard  damask,  illustrated  and  described ;  To  damaskeen  iron  and  steel 
with  platinum ;  Damaskeening  with  gold  or  silver  ....  281 

Imitation  of  damask ;  To  produce  damask  in  relief  upon  gun-barrels ; 

Damaskeened  surface  upon  steel  guns . 282 

Damasked  bronze ;  Iridescent  colors  upon  metals ;  Moirfe  metallique  .  283 
Colored  moir6  on  tin-plate ;  Moirfe  on  brass  ......  285 

To  decorate  tin-plate . 286 

New  method  of  decorating  metals . 287 


XVI 


CONTENTS. 


Nielled  silver  ............  288 

Composition  of  various  niels ;  Composition  of  Tula  .....  289 

Muffles  for  nielling  and  enamelling  illustrated  and  described  .  .  .  290 

To  imitate  nielled  work  by  the  galvanic  method  ;  Oxidized  silver  .  .  292 

New  protecting  coat  on  metals;  Photo-chemical  process  of  decorating 
metal  ....  .........  294 

To  prepare  zinc  for  painting;  How  to  prepare  a  rough  surface  in  grounding 
metals  for  subsequent  decoration  ........  295 

To  coat  stoves,  tools,  etc. ;  Ward’s  inoxidizing  process  ;  Inoxidizing  process 
for  cast-iron  ............  296 

The  Barfif  process  for  preserving  iron  and  steel  from  rust  ....  297 

Enamelling  metals  ;  Ground,  or  ground  mass  ;  Covering  mass  or  glaze  .  298 
Enamel  for  iron  objects ;  To  enamel  cast-iron  utensils  ....  299 

Very  white  and  firmly  adhering  enamel  for  cast-iron  articles  as  prepared  in 
England  ............  300 

Another  method  of  enamelling  cast-iron ;  Mottled  enamel  ....  301 

Enamel  for  cast-iron  pipes  according  to  Amtmann  ;  Glaze  for  iron  pipes  .  302 
Emaille  de  fer  contre-oxydi ;  Glass  enamel  for  iron ;  Enamel  for  copper 
cooking  utensils  ...........  303 

Colored  enamels  ;  Enamels  for  goldsmiths  ......  304 

White  enamel  for  ornamental  articles  .......  305 

Emaille  Cloisonn6e  ;  Enamelling  watch  dials  ......  306 

Emaille  plaque-vitro-metallique ;  Emaille  champ  lev£e  ;  Phosphorescent 
enamel ;  To  secure  enamel  and  glass  to  metal  by  means  of  the  electric 
current;  Engraving  on  copper  ........  307 

Engraving  on  silver  or  gold  .........  308 

To  engrave  aluminium;  Soft  wax  for  engravers;  Wax-mass  for  copper 
engravers;  Etching-ground  .........  310 

Callot’s  etching-ground ;  Etching  on  copper ;  Etching  on  brass  and  silver  ; 

Etching  on  steel  .  .  .  .  .  .  .  .  .  .  -311 

Etching  names  on  steel  and  glass  .  .  .  .  .  .  .  .312 

Etching  on  zinc ;  Etching  solution  for  brass  .  .  .  .  .  .  313 

Glyphogene  or  etching  fluid  for  steel ;  Etching  without  etching-ground  .  314 
To  produce  figures  in  relief  .  .  .  .  .  .  .  .  -315 

Metallography  (method  for  producing  drawings  of  all  kinds  in  relief  upon 
metal)  according  to  Zach  .  .  .  .  .  .  .  .  .316 

XI. — Electro-plating,  Brassing,  Coppering,  Galvanizing,  Gilding, 
Nickelling,  Silvering,  Tinning,  Etc. 

Preparatory  manipulation  of  articles  to  be  plated  .  .  .  .  .  317 

Freeing  from  grease ;  Dipping  .........  318 

Composition  of  preliminary  pickle,  of  pickle  for  bright  lustre  and  of  pickle 


CONTENTS. 


xvn 


for  a  dead  lustre ;  Mixture  for  the  production  of  a  dull-grained  surface 
upon  brass  ;  Mixtures  for  dipping  German  silver,  silver,  zinc  and  tin  .  319 
Water  used  for  the  preparation  of  the  galvanic  baths ;  Composition  and 
temperature  of  the  baths  ;  Batteries  used  for  electro-deposition  .  .  320 

Bunsen’s  battery  illustrated  and  described  .  . . 321. 

Manner  of  locating  batteries . 322 

Terms  used  in  electrolytic  deposition  of  metals;  Table  of  chemical  and 
electro-chemical  equivalents  .........  323 

Practical  application  of  the  table ;  Preparation  of  zinc  for  batteries  .  .  324 

Aluminium  bath ;  Antimony  baths ;  Arsenic  baths  .....  325 

Brass  baths ;  Brass  bath  from  cupric  sulphate  and  zinc  sulphate ;  Brass  bath 

for  zinc . 326 

Brass  bath  for  cast-iron,  wrought-iron  and  steel ;  Solution  for  transferring 

any  copper-zinc  alloys  serving  as  anode . 327 

Cobalt  baths  ............  328 

Electro -plating  with  cobalt  by  contact;  Copper  baths;  Copper  baths  for 
iron  and  steel  articles  ;  To  be  used  at  an  ordinary  temperature  .  .329 

To  be  used  at  from  140°  to  158°  F . 330 

Copper  bath  without  potassium  cyanide ;  The  Elmore  process  of  electro- 
depositing  copper  for  tubes  and  wire  bars  .  .  .  ...  .  331 

To  get  a  copper  deposit  on  wax ;  Brush  coppering  for  iron  and  steel  .  334 
To  copper  iron  ............  335 

To  copper  iron  and  steel ;  To  copper  cast-iron  ;  To  coat  iron  articles  with 
copper,  brass  or  bronze  ..........  336 

To  coat  tin,  cast-iron,  or  zinc  with  copper  ;  To  copper  zinc  plates  .  .  337 

Gold  baths  ............  338 

Gilding  with  a  dead  lustre . 341 

Gilding  by  contact  and  dipping,  cold  gilding  and  gilding  by  adhesion ;  Gold 
solution  for  gilding  by  contact  ...  .....  342 

Baths  for  gilding  by  touching  with  a  zinc  rod  ......  343 

Baths  for  gilding  by  dipping  .........  344 

Cold  gilding,  or  gilding  by  the  rag  .  .  .  .  .  .  .  .  345 

To  gild  by  adhesion  ;  To  gild  steel ;  To  fire-gild  silver  objects  .  .  .  346 

To  fire-gild  and  fire-silver  metals  which  cannot  be  amalgamated,  for 
instance,  iron  and  steel ;  To  give  gilt  articles  a  beautiful  rich  appear¬ 
ance;  To  improve  bad  tints  of  gilding  ;  To  gild  articles  of  metal  .  .  347 

Imitation  gilding ;  Gilding  powder  for  copper,  silver,  brass,  etc. ;  Gilders’ 

wax  for  fire-gilding . .  .  .  .  .  348 

Quicksilver  water  ;  Iron  baths  .........  349 

Lead  baths;  To  coat  metals  with  lead  .  .  .  .  .  .  -35* 

Improved  method  of  covering  articles  of  iron  with  lead  ....  352 

Leyson’s  process  of  leading . 353 

2 


xviii 


CONTENTS. 


Alloys  for  hot  leading ;  Nickel  baths ;  Preparation  of  the  metals  to  be 

nickelled . 354 

Composition  of  the  most  simple  nickel  bath ;  Weston’s  solution ;  Pott’s 

solution . 356 

Powell’s  solutions ;  Nickel  bath  much  used  in  this  country ;  Baths  for 
rapidly  nickelling  cheap  articles  .  .  .  .  .  .  .  -357 

Nickel  baths  for  special  purposes  .  .  .  .  .  .  .  .  358 

New  nickel  baths . 359 

Nickelling  of  knife-blades,  sharp  surgical  instruments,  etc.  .  .  .  360 

Phenomena  which  may  occur  in  nickelling  and  the  means  of  avoiding  them  361 
To  improve  defective  nickelling  ;  To  nickel  polished  objects  of  iron  or  steel 

without  the  use  of  a  battery . 363 

To  imitate  nickel-plating  .  .  .  .  .  .  .  .  .  .  364 

Platinum  baths ;  Platinum  bath  patented  by  the  Bright  Platinum  Plating 
Co.,  of  London  .  .  .  .  .  .  .  .  .  .  .  365 

Platinum  bath  recommended  by  Prof.  Silvanus  P.  Thompson ;  To  platinize 
copper;  To  platinize  by  the  wet  method  ......  366 

To  coat  metals  with  platinum  in  a  cheap  way  ......  367 

Silver  baths . 368 

Silvering  by  contact . 370 

Silvering  by  dipping ;  Blanching . 371 

Cold  silvering  ;  Composition  of  argentiferous  pastes . 372 

Graining . 373 

Nuremberg  graining  powder ;  Operation  of  graining  .....  374 

Gold  baths  with  yellow  prussiate  of  potash . 376 

Birmingham  silvering  ..........  377 

Mechanical  silvering  according  to  Bertrand ;  Silvering  of  iron  according  to 
Rinmann;  To  silver  Bessemer  steel  and  utensils  manufactured  from  it  .  378 

Alloy  for  silvering . 379 

Tin  baths . 380 

Tinning  by  contact;  Tinning  by  dipping;  Tinning  by  boiling  articles  of 
iron  and  steel  .  .  .  .  .  .  .  .  .  .  -381 

To  tin  small  brass  or  copper  objects;  Another  method;  Eisner’s  bath; 
Stolba’s  method  of  tinning  .........  382 

Cold  tinning;  Tinning  hard  steel  or  case-hardened  articles  .  .  .  383 

Improved  process  of  tinning  metals  ........  384 

To  tin  kettles ;  To  tin  lead  plates  ........  385 

To  prepare  tinned  lead  pipes;  To  make  “  Fonte  argentine  ”  or  tinned  cast- 
iron  ;  Zinc  baths  ...........  3^6 

To  zinc  copper  and  brass  without  a  battery;  Another  process;  Tc  zinc  iron 
in  the  cold  way  ...........  3^7 

Galvanizing  sheet-iron  . . .  3^8 


CONTENTS. 


xix 


To  galvanize  old  and  new  parts . 392 

Metallic  coating  upon  flowers  and  insects  by  the  galvanic  way ;  To  coat 
iron  articles  with  other  metals  according  to  Newton  ....  393 

XII. — Fluxes  and  Lutes. 

Fluxes ;  Substances  used  as  fluxes ;  Best  flux  for  alloys  of  copper  and  tin ; 

Good  flux  for  brass ;  Black  flux . 394 

Gray  flux ;  White  flux . 395 

Quick  flux ;  Flux  for  reducing  arsenic ;  Cornish  reducing  flux ;  Refining 
flux ;  Crude  flux ;  Fluxes  for  arsenical  compounds ;  Moreau’s  reducing 

flux ;  Salt  cake ;  Lutes . 396 

Stourbridge  clay ;  Windsor  loam;  Fat  lutes . 397 

XIII. — Lacquers,  Paints  and  Varnishes. 

Japanning  tin . 397 

Vermilion  ground;  Black  grounds  for  japanning;  Black  japan  for  tin 

lanterns . 400 

Asphalt  lacquer  on  iron ;  To  lacquer  brass  .  .  .  .  .  .401 

Lacquer  for  brass ;  Pale  lacquer  for  brass ;  Pale  gold  lacquer  for  brass ; 
Gold-colored  lacquer  for  brass  watch  cases,  etc. ;  Gold  lacquer  for  metallic 

articles ;  Gold  lacquer  for  tin  plate . 402 

Green  lacquer;  Iron  lacquer  for  blacksmiths,  locksmiths  and  founders; 
Lacquers  for  gold ;  Pale  lacquer  for  gold ;  Lacquer  for  philosophical 

instruments . 403 

Lacquer  for  steel;  Lacquer  for  tin -foil ;  Metallic  gold  color ;  To  lacquer 

optical  instruments . 404 

Coating  for  bars  of  spring  steel  not  acted  upon  by  acids;  Black  coating  for 

iron . 406 

New  rust  preventive;  To  protect  iron  and  steel  from  rust;  To  protect 

lightning-rods,  metal-roofs,  etc.,  from  rust . 407 

To  protect  lead  pipes;  Painting  of  iron . 408 

Paint  for  sheet-iron  roofs . 409 

Paint  for  preserving  zinc  roofs ;  Black  varnish  for  iron  and  steel ;  Black 

varnish  for  zinc . 410 

Bright  asphalt  varnish  for  sheet  metals;  Colored  varnish  for  sheet  metals  .  41 1 
Green  varnish  for  metals ;  Green  transparent  varnish ;  Varnish  for  iron 
work;  Varnish  for  common  work  ;  Varnish  for  iron  patterns  .  .  412 

Varnish  for  metals  according  to  Max  Innes . 413 


XIV. — Soldering  and  Solders. 

Object  of  soldering ;  Definition  of  solders ;  Agreement  of  metals  and  solders  413 


XX 


CONTENTS. 


Preparation  of  the  work  for  hard  soldering ;  Definition  of  brazing ;  Descrip¬ 
tion  of  the  soldering  iron  .........  414 

Tinning  of  the  copper  bit;  Definition  of  a  “  wiped  joint;  ”  The  blow-pipe 

and  its  uses . 41 5 

Blast  used  by  pewterers ;  Heat  required  for  hard  soldering ;  The  brazier’s 
hearth;  Preparation  of  the  meeting  edges;  Operation  of  hard  soldering 
or  brazing  ............  416 

Brazing  of  iron ;  Composition  and  nature  of  spelter ;  Use  of  the  blow-pipe 
in  hard  soldering  and  brazing  .  .  .  .  .  .  .  .417 

Fluxes  and  soldering  liquids  used  in  soldering;  Preparation  of  soldering 

liquid . 418 

Soldering  paste ;  Soldering  fat ;  Miiller’s  soldering  liquid  .  .  .  .  419 

Gauduin’s  soldering  liquid  ;  New  soldering  liquid;  Soft  solders  .  .  420 

Preparation  of  soft  solder ;  Bismuth  solder;  Hard  solders;  Spelter  solder  .  421 
Tables  showing  the  composition  of  various  kinds  of  hard  solders  .  .422 

Solders  for  aluminium;  To  solder  aluminium  with  the  blow-pipe;  To 
solder  aluminium  with  the  common  soldering  iron ;  Soldering  of  alumin¬ 
ium  bronze  ............  423 

Hulot’s  solder  for  aluminium  bronze ;  Solders  for  aluminium  bronze  jewelry  ; 
Hard  solder  for  10  per  cent,  bronze;  Middling  hard  solder  for  10  per 
cent,  bronze ;  Soft  solder  for  aluminium  bronze ;  Argentan  solders  ; 
Readily  fusible  argentan  solder ;  Less  readily  fusible  argentan  solder ; 
Soldering  cast-iron  ..........  424 

To  solder  cast-iron  objects;  Soldering  with  dry  lead  chloride;  Gold 
solders  .............  425 

Solder  for  enamelled  work;  Refractory  solder;  More  readily  fusible  solder; 

To  remove  tarnish  from  gold  after  hard  soldering;  Silver  solders  .  .  426 

Hard  silver  solders ;  Hard  silver  solder  for  the  first  soldering;  Softer  hard 
silver  solder  for  after  soldering ;  Alloy  for  cold  soldering  .  .  .  427 

Copper  the  best  material  for  joining  iron  to  iron;  To  solder  copper  wire; 

To  solder  saws  ...........  428 

To  solder  without  a  soldering  iron ;  To  color  soft  solder ;  To  make  platinum 
adhere  to  gold  ...........  429 

Autogenous  soldering  ..........  430 

XV. — Welding  and  Welding  Compounds. 

Analogy  to  welding ;  Chief  difficulty  in  welding  iron;  Heat  required  for 
welding  iron  and  cast-steel  .........  430 

Purpose  of  welding  powders ;  General  rule  for  welding  .  .  .  .43* 

To  weld  cast-steel ;  Fluxes  used  in  welding  cast-steel  ....  432 

American  welding  compound  for  welding  steel  to  steel ;  Another  formula  ; 


CONTENTS. 


xxi 

Welding  compound  to  weld  steel  to  wrought-iron  at  a  red  heat;  To  weld 
steel  to  iron  or  steel ;  Welding  compound  for  welding  wrought-iron  to 


wrought-iron  at  a  red  heat . 433 

To  thoroughly  and  firmly  unite  by  welding  steel  with  steel,  cast-steel  with 
cast-steel  and  cast-steel  with  iron ;  Improved  method  of  welding  .  .  434 

To  weld  copper;  To  make  old  steel  rails  new  ......  435 

Welding  of  platinum ;  Electric  welding ;  The  apparatus  ....  436 

Generation  of  electricity  by  the  direct  and  indirect  systems  .  .  .  437 

The  process  of  electric  welding ;  Simplicity  of  the  process  ....  438 

Time  required  for  making  an  electric  weld ;  Applications  of  electric  weld¬ 
ing  ;  Strength  of  electric  welds  ........  439 


Electrohephestos ;  MM.  de  Bernados’  and  Olszewsky’s  method  of  electric 
welding;  Experiments  with  Bernados’  and  Olszewsky’s  electric  welding 
apparatus  at  Tegel,  near  Berlin ;  Chemical  change  produced  in  steel  and 
iron  by  the  action  of  the  arc  in  electric  welding  .....  440 
Storage  batteries  constructed  by  M.  de  Bernados  illustrated  and  described  441 
Manner  of  operating  Bernados’  and  Olszewsky’s  apparatus  illustrated  and 
described . 442 

XVI. — Wire — Manufacture,  Brassing,  Coppering,  Electroplating, 


Galvanizing,  Etc. 

What  wire-drawing  consists  in ;  Drawing  properties  of  metals,  on  what  they 

depend . 445 

Definitions  of  the  qualities  of  wires ;  Plough  steel ;  Characteristics  of  wire 
rods,  on  what  they  depend ;  Amount  of  carbon  which  may  be  present  in 
steel  rods ;  Deleteriousness  of  sulphur  and  phosphorus  ....  446 

Breaking  strengths  of  various  wires ;  Manner  of  rolling  rods  at  Garrett’s 
wire-rod  mill,  near  Chicago,  Illinois,  and  in  England  ....  447 

The  entire  series  of  grooves  of  a  wire-rod  roll  illustrated ;  Construction  of 
an  oval  groove  illustrated  .........  448 

Preparation  of  wire-rods  for  drawing ;  A  wire-drawing  mill  illustrated  and 

described . 449 

Wire-drawers’  soap  or  grease . 450 

F.  Vogel’s  pickle ;  Lubricant  in  drawing  Bessemer  wire  recommended  by 
Chas.  H.  Morgan ;  Annealing  of  wire  during  the  drawing  process ; 
Annealing  pots  .  .  .  .  .  .  .  .  .  .  .  451 

W.  Rath’s  method  of  preventing  the  formation  of  scales  during 
annealing;  Drawing  drums ;  Ripping  blocks ;  Tempering  or  “  patenting  ” 

wires . 452 

Half-round  wire ;  Schniewindt’s  apparatus  for  producing  half-round  wire 
illustrated  and  described  ;  Barbed  wire  ;  Typical  shapes  of  barbed  wire 


illustrated  and  described  .........  453 


xxii 


CONTENTS. 


Barbed  fencing  wire  manufactured  by  Bernhard  Ebeling,  of  Bremen,  and 
C.  Klauke,  of  Miincheberg,  near  Berlin  ......  454 

Moen’s  machine  for  the  manufacture  of  barbed  wire  illustrated  and 
described  ;  Barbed  wire  from  a  single  wire ;  Barbed  wire  manufactured 
by  the  “Westphalische  Union  ”  of  Hamm  .  .  .  .  *455 

Phosphorized  bronze  or  brass  wire  ;  Hardening  of  wire ;  Ramsden’s  method 
of  hardening  wire  illustrated  and  described  ......  456 

Tables  relating  to  wire  by  John  A.  Roebling’s  Sons  Co.,  of  Trenton, 

N.J.  .  .  •  . . 459 

Table  of  wire  gauges,  in  decimal  parts  of  an  inch  .....  460 

Table  indicating  size,  weight  and  length  of  iron  and  steel  wire  .  .  .  461 

Table  of  weight  per  1000  feet  of  copper  wire  ......  462 

Table  of  weight  per  mile  of  copper  wire ;  To  brass  wire  in  the  galvanic 

way  . . 463 

To  electro-brass  wire ;  Manufacture  of  brass  wire ;  To  copper  iron  wire  .  464 
To  galvanize  wire ;  Roberts’  apparatus  for  galvanizing  wire  illustrated  and 

described . 465 

Vogt’s  arrangement  for  closing  vessels  through  which  the  wire  is  conducted 
in  a  straight  line,  illustrated  and  described ;  Wittle  and  Kamper’s  arrange¬ 
ment  for  removing  superfluous  zinc,  illustrated  and  described ;  Roberts’ 
apparatus  for  the  same  purpose,  illustrated  and  described  .  .  .  466 

To  gild  metallic  wire  and  wire  cloth ;  J.  W.  Spaeth’s  machine  for  gilding 

wire  and  wire-cloth  illustrated  and  described . 468 

Manufacture  of  gold  wire ;  To  nickel  wire  . . 470 

To  tin  wire  and  wire-gauze  .........  471 

To  harden  steel  piano  wire  ;  Coating  which  does  not  readily  oxidize  upon 
steel  and  iron  wire  ..........  473 

XVII. — Miscellaneous. 

Manufacture  of  basic  open-hearth  steel;  J.  H.  Darby’s  experiments,  and 


description  of  furnaces  used . 474 

Composition  of  the  charge  ;  Analysis  of  the  soft  steel  obtained  ;  The  Carls- 

son  Bessemer  process . '  .  .  .  475 

Malleable  cast-iron . 476 

Lead  lapping  illustrated  and  described . 479 

Sawing  iron  and  steel ;  Manufacture  of  nicking  saws  ....  481 
Hardening  and  tempering  of  the  saws  ;  Speed  at  which  the  saws  should  be 
run ;  Manner  of  cutting  off  a  piece  of  hardened  steel  ....  482 
Utilization  of  red-brass  turnings  ;  Recovery  of  copper  ....  483 
Recovery  of  gold  from  gold  baths,  etc. ;  The  wet  process  ....  484 
Recovery  of  gold  and  silver  from  sweepings  and  other  refuse  from  the 
manufacture  of  gold  ware,  etc. ;  Ungilding  ......  485 


CONTENTS. 


xxiii 


Utilization  of  nickel  waste;  Adams’  nickel-plating  salt;  To  recover  nickel 
from  old  solutions  ...........  486 

Recovery  of  silver  from  old  cyanide  plating  solutions,  etc. ;  The  wet 

method ;  Preparation  of  granulated  silver . 487 

Desilvering ;  Recovery  of  platinum  from  platinum  solutions  .  .  .  488 

Recovery  of  tin  from  tin-plate  waste  ;  Another  method ;  To  separate  lead 
from  zinc;  How  Japanese  swords  are  made  ......  489 

To  make  knives  from  old  files ;  Manufacture  of  metal  pipes,  F.  Madeley’s 

patent . 491 

Improvement  in  the  treatment  of  steel,  C.  Jones’  patent ;  Ink  for  writing  on 
tin;  Ink  for  writing  on  zinc;  Insulating  coverings  for  steam-pipes,  etc.  .  492 
Another  insulating  material  for  steam-pipes ;  Insulating  mass  for  steam- 
boilers,  etc. ;  Insulating  material  for  electrical  conduits ;  Flexible  insula¬ 
ting  mass  for  electrical  conduits ;  Gold  beating  .....  493 

Composition  of  the  cutch ;  Composition  of  the  shoder  ....  494 

Lining  for  furnaces ;  Matrix  mass  for  the  reproduction  of  metals,  coins, 
etc.;  Oil  of  mustard  as  a  lubricator;  Spinning  of  metals  illustrated  and 
described  ............  495 

Spinning  tools,  illustrated  and  described  .......  496 

To  cut  sheet-brass  by  chemical  means ;  To  roughen  sheet-brass  for  painting ; 

To  cut  iron  plates  with  the  assistance  of  sulphuric  acid;  To  make  a  hole 
in  hard  steel;  To  detach  gold  from  metallic  articles  ....  499 

To  give  metals,  lead,  tin,  zinc,  etc.,  the  capacity  of  firmly  adhering  to  other 
metals,  and  to  amalgamate  with  them;  To  keep  steel  from  rusting;  To 
prevent  metals  from  rusting ;  To  prevent  the  rusting  in  of  screws;  To 
loosen  rusted  screws ;  To  prepare  good  crucibles  .....  500 

To  purify  gold  in  the  dry  way  (by  cementation)  according  to  Philipp  ;  To 
repair  cracked  church  bells ;  To  restore  burnt  cast-steel  .  .  .  501 

To  restore  burnt  steel  tools  ;  To  sharpen  files . 502 

Process  of  sharpening  files  with  the  sand  blast  ......  503 

To  sharpen  tools;  New  method  of  securing  flues  .....  504 

Solidification  of  powdered  metal ;  Combustibility  of  iron  ....  505 

Colors  expressing  high  temperatures  ........  506 

Rails  and  fastenings  per  mile  of  railroad . 507 

Index . 509 


THE 


METAL  WORKER’S  HANDY-BOOK 

OF 

RECEIPTS  AND  PROCESSES. 


i. 

CHEMICAL  RELATIONS  OF  THE  METALS. 

The  chemist  distinguishes  49  different  metals,  and  understands 
under  the  term  “metals”  simple  bodies  (elements)  which  form 
certain  combinations  with  oxygen,  differing  essentially  from  the 
combinations  with  oxygen  of  the  non-metals. 

The  practical  metal  worker  makes  use  only  of  a  small  portion  of 
the  metals ;  he  works  up  by  themselves  :  iron,  copper,  zinc,  tin, 
lead,  silver,  gold,  platinum,  aluminium  and  nickel.  In  combination 
with  other  metals,  i.  e.,  as  alloys,  are  used :  antimony,  bismuth, 
cadmium,  manganese,  tungsten,  chrojnium,  arsenic  and  iridium. 

Although  in  working  metals  their  physical  properties  chiefly  come 
into  consideration,  and  the  practical  metal  worker  has  principally 
to  deal  with  their  fusibility,  ductility  and  divisibility,  he  must  not 
be  ignorant  of  their  chemical  properties,  because,  on  the  one  hand, 
the  gaining  of  metals  is  based  upon  chemical  processes,  and,  on  the 
other,  cases  frequently  occur  in  practice,  especially  in  processes 
relating  to  the  ornamentation  of  the  finished  article,  which  can  be 
explained  only  by  a  knowledge  of  chemistry. 

For  this  reason  it  is  considered  necessary  to  devote  some  space 
to  the  chemistry  of  metals  and  their  behavior  towards  some  non- 
metallic  bodies.  The  experiments  here  given,  the  execution  of 
3  (33) 


34 


THE  METAL  WORKER’S  II ANDY-BOOK. 


which  by  the  reader  is  urgently  advised,  may  at  the  same  time 
serve  as  a  preparatory  course  for  the  qualitative  analysis  of  metals 
and  alloys  given  in  Section  III. 

Behavior  of  Metals  towards  Oxygen. — Freshly-fractured  surfaces 
of  metals  exhibit  a  characteristic  lustre — metallic  lustre — which 
remains  constant  with  a  few  metals  only,  whilst  with  others  it  can 
be  preserved  only  by  certain  agents  (polish,  lacquer).  Without 
such  agents  the  lustre  is  soon  lost  in  consequence  of  the  action 
of  the  air,  heat  or  moisture. 

This  alteration  is  most  plainly  illustrated  by  potassium.  Potas¬ 
sium  is  a  metal  of  such  softness  that  it  can  be  cut  with  a  knife  with 
greater  ease  than  lead.  The  freshly-cut  surface  has  a  silver-like 
lustre  which,  however,  instantly  tarnishes  on  exposure  to  air,  and 
the  metal  is  converted  into  a  white  body  which  readily  dis¬ 
solves  in  water.  For  this  reason  potassium  by  itself  cannot  be  used 
for  technical  purposes,  and,  for  reasons  to  be  explained  later  on,  it 
can  only  be  preserved  by  keeping  it  in  a  sealed  tube  free  from 
oxygen  or  beneath  the  surface  of  naphtha. 

The  white  body  mentioned  above  has  a  larger  volume  and 
greater  weight  than  the  potassium  used ;  consequently  the  metal 
must  have  combined  with  other  bodies,  such  as  occur  in  the  atmos¬ 
phere.  And  such  is  actually  the  case,  one  constituent  of  the 
air — oxygen— having  combined  with  the  metal.  The  body  formed 
— potassium  oxide — having  further  absorbed  water  from  the  air, 
potassium  hydrate  is  formed. 

The  union  of  potassium  with  oxygen  is  still  more  rapidly  effected 
by  throwing  a  piece  the  size  of  a  pea  upon  water.  Its  specific 
gravity  being  only  0.865,  A  swims  upon  the  surface.  The  water, 
however,  is  instantly  decomposed,  hydrogen  being  rapidly  dis¬ 
engaged  ;  and  the  heat  evolved  is  sufficient  to  inflame  the  gas, 
which  burns  with  a  violet  flame  from  the  volatilization  of  a  portion 
of  the  potassium.  In  this  case  oxygen  is  withdrawn  from  the 
water.  The  potassium  hydrate  also  formed  in  this  experiment  has 
instantly  dissolved  in  the  water.  To  prove  that  the  water  actually 
contains  in  solution  the  combination  of  a  metal  with  oxide — a 
metallic  oxide — it  is  only  necessary  to  dip  a  piece  of  red  litmus 


CHEMICAL  RELATIONS  OF  THE  METALS. 


35 


paper  into  the  water.  In  pure  water  the  litmus  paper  is  not  changed ; 
however,  in  water  containing  a  metallic  oxide  in  solution,  it  is 
colored  blue  as  far  as  dipped  in. 

The  process  of  the  absorption  of  oxygen  just  described  is  called 
oxidation,  the  combination  of  the  metal  with  oxygen,  an  oxide,  and, 
in  case  the  oxide  has  further  absorbed  water,  this  new  combination 
is  termed  an  hydroxide. 

The  oxidation  of  metals  takes  place  with  special  ease  under  the 
influence  of  heat.  A  piece  of  magnesium  wire  held  in  a  spirit 
flame  burns  with  a  bright  white  light,  the  product  of  combustion 
being  magnesium  monoxide  or  magnesia. 

Zinc  is  a  readily  fusible  metal,  it  becoming  liquid  at  7730  F. 
By  heating  it  to  9320  F.  its  affinity  for  oxygen  becomes  so  apparent 
that  on  pouring  it  from  the  crucible  it  burns  with  a  splendid 
greenish  light  and  when  cool  forms  a  white  flaky  body — zinc  oxide. 

Hence  the  combustion  of  metals  is  nothing  else  but  their  union 
with  oxygen — an  oxidation.  However  the  oxidation  effected  by 
heat  is  not  always  a  visible  phenomenon  of  combustion. 

By  heating  a  piece  of  copper-sheet  over  an  alcohol  flame  the 
latter  becomes  green,  this  being  an  indication  of  the  combustion 
of  the  copper ;  moreover,  the  color  of  the  copper  also  changes,  it 
becoming  gradually  yellow,  violet  and  blue  and  finally  black. 
The  black  body  formed  is  cupric  oxide.  By  immersing  the  sheet 
after  the  formation  of  the  oxide  in  water,  the  oxide  scales  off  and 
the  sheet  shows  a  brown-red  appearance  different  from  that  of 
metallic  copper.  This  brown-red  layer  can  be  readily  removed  by 
mechanical  means  (scraping,  polishing),  but  by  repeated  heating  is 
also  converted  into  oxide.  Hence  it  is  also  a  combination  of 
copper  with  oxygen,  but  it  contains  only  half  as  much  oxygen  as 
cupric  oxide,  and  is  called  cuprous  oxide. 

Cupric  oxide  contains  63.5  parts  of  copper  to  16  of  oxygen, 
whilst  cuprous  oxide  contains  127  parts  of  copper  to  16  of  oxygen. 

Most  metals  unite  with  oxygen  in  two  proportions ;  some,  how¬ 
ever,  for  instance,  lead  and  manganese,  will  combine  with  more 
oxygen  than  is  contained  in  their  oxides.  Such  higher  grades  of 
oxidation  are  termed  super-oxides,  whilst  the  terms  protoxide  and 


36 


TIIE  METAL  WORKER’S  HANDY-ROOK. 


suboxide  are  applied  to  combinations  of  oxygen  containing  less 
oxygen  than  the  oxides. 

Platinum,  gold,  silver  and  mercury  do  not  combine  with  oxygen 
in  the  manner  above  described.  They  retain  their  metallic  lustre, 
and  their  oxides  can  only  be  prepared  with  difficulty.  To  dis¬ 
tinguish  them  from  the  more  readily  oxidizable  base  metals  they  are 
called  noble  metals. 

Combinations  of  the  Metals  with  Chlorine. — To  prepare  chlorine 
for  experiments  it  may  be  separated  from  hydrochloric  acid,  a 
combination  of  chlorine  and  hydrogen.  For  this  purpose  pour 
over  20  parts  by  weight  of  finely  pulverized  pyrolusite  (peroxide 
cf  manganese)  in  a  flask,  60  parts  by  weight  of  hydrochloric  acid, 
and  apply  a  gentle  heat ;  a  heavy  yellow  gas  is  disengaged  which 
is  the  substance  in  question.  The  reaction  consists  in  an  inter¬ 
change  between  the  two  atoms  of  oxygen  of  the  pyrolusite  and 
four  atoms  of  chlorine  from  the  hydrochloric  acid,  the  oxygen 
uniting  with  the  hydrogen  to  form  water,  while  of  the  chlorine 
one-half  unites  with  the  manganese,  forming  a  chloride,  and  the 
other  half  is  given  off  as  gas. 

The  disengaged  chlorine  being  very  poisonous  if  inhaled,  great 
care  must  be  exercised  in  its  preparation.  As  a  precautionary 
measure  frequently  wave  a  cloth  moistened  with  a  few  drops  of 
spirit  of  wine  and  spirit  of  sal-ammoniac  through  the  air.  The 
chlorine  contained  in  the  air  combines  with  the  spirit  of  sal- 
ammoniac  to  a  body  which  is  not  injurious  to  the  respiratory 
organs. 

To  collect  the  chlorine  in  a  bottle  fill  the  latter  with  lukewarm 
water  and  fasten  a  bent  glass-tube  to  the  boiling  flask  by  means  of 
a  perforated  tube,  allowing  the  free  end  of  the  tube  to  dip  in  a 
dish  filled  with  water.  The  chlorine  escapes  in  bubbles  from  the 
aperture  in  the  tube.  To  collect  it  close  the  bottle  filled  with  luke¬ 
warm  water  with  the  thumb  or  a  moistened  glass-plate  and  immerse 
it,  mouth  down,  in  the  dish  filled  with  water.  On  removing  the 
thumb  or  the  glass-plate  the  water  does  not  run  out,  and  the  filled 
bottle  can  be  readily  brought  over  the  discharge-aperture  of  the 
glass-tube.  The  escaping  chlorine  gradually  displaces  the  water. 


CHEMICAL  RELATIONS  OF  THE  METALS. 


37 


When  all  the  water  is  displaced  and  the  bottle  filled  with  chlorine, 
it  is  taken  out  after  having  previously  been  corked  under  water. 
Powdered  antimony,  if  allowed  to  fall  into  a  bottle  filled  with 
chlorine,  burns  with  a  white  smoke  and  the  appearance  of  a  fiery 
rain. 

A  piece  of  Dutch  gold  (metal-leaf)  also  burns  with  a  lively  flame 
in  chlorine,  the  product  of  combustion  dissolving  with  a  blue-green 
color  in  water. 

Genuine  gold  dissolves  in  chlorine  water,  the  solution  being  of 
a  slightly  yellowish  color.  Hence  chlorine  furnishes  a  sure  means 
of  distinguishing  genuine  from  spurious  gold. 

The  combinations  of  chlorine  with  metals  are  called  metallic 
chlorides.  Metallic  chlorides  in  solutions  are  obtained  by  intro¬ 
ducing  metals  or  metallic  oxides  into  hydrochloric  acid,  iron 
and  zinc  being  especially  soluble  in  the  acid.  If,  for  instance, 
small  pieces  of  zinc  are  brought  into  a  bottle  provided  with  two 
mouths  (Fig.  i),  and  hydrochloric  acid  diluted  with  water  be 
poured  through  a  funnel  placed  air-tight  upon  the  bottle,  the  zinc  is 
dissolved  with  a  vigorous  development  of  gas.  To  more  closely 
examine  the  evolved  gas,  secure  to  the  other  mouth  of  the  bottle  a 
bent  glass  tube,  the  free  end  of  which  is  drawn  out  to  a  fine  point. 

The  gas  escaping  at  a  readily  ignites.  The  flame  does  not  emit 
light,  but  gives  out  such  an  intense  heat  that  iron  wire  may  be 
fused  in  it  and  platinum  wire  brought  to  a  red  heat.  The  ignition 
of  the  gas,  however,  must  not  be  effected  too  quickly,  because  so 
long  as  the  atmospheric  air  is  not  completely  removed  from  the  bottle 
and  the  tube,  a  mixture  is  formed  which  ignites  with  violent  detona¬ 
tion  by  being  brought  in  contact  with  a  lighted  match  or  a  red  hot 
wire.  The  gas  evolved  is  called  hydrogen  and  the  mixture  of  hydrogen 
and  air,  oxyhydrogen  gas.  By  inverting  a  glass  bell  (Fig.  i)  over 
the  hydrogen  flame  the  aqueous  vapors  formed  condense  and  run 
down,  drop  by  drop,  on  the’ sides  of  the  glass-bell. 

In  order  to  obtain  a  clear  idea  of  the  above-described  process  of 
the  development  of  hydrogen,  it  must  be  remembered  that 
hydrochloric  acid  consists  of  chlorine  and  hydrogen.  Chlorine, 
however,  has  a  stronger  affinity  for  zinc  than  for  hydrogen,  and, 


38 


THE  METAL  WORKER'S  IIANDY-BOOK. 


therefore,  by  bringing  zinc  into  hydrochloric  acid,  the  chlorine 
leaves  its  associate,  which  escapes,  while  the  chlorine  forms  with 


the  zinc  a  combination  soluble  in  water — chloride  of  zinc.  In  dis¬ 
solving  metallic  oxides  in  hydrochloric  acid  no  hydrogen  is  liber¬ 
ated,  because  the  hydrogen  separating  from  the  acid  instantly 
combines  with  the  oxygen  of  the  oxide  to  water.  Thus,  for  in¬ 
stance,  by  bringing  cupric  oxide  into  hydrochloric  acid  a  green 
solution  results  from  which,  by  evaporation,  the  chloride  of  copper 
is  obtained  in  green  crystals.  A  development  of  hydrogen  does 
not  take  place,  because  : 


Cupric  oxide  = 
Hydrochloric  acid  = 
Products : 


copper  -p  oxygen, 

chlorine  -y  hydrogen, 

chloride  of  copper  +  water. 


Gold,  platinum  and  mercury  do  not  dissolve  in  hydrochloric 
acid.  However,  it  has  previously  been  stated  that  gold  dissolves 
in  pure  chlorine.  If,  now,  hydrochloric  acid  is  to  be  used  for  the 
solution  of  gold,  a  body  has  to  be  added  to  the  acid  which  with¬ 
draws  from  it  the  hydrogen  and  liberates  the  chlorine.  Nitric  acid, 
being  very  rich  in  oxygen,  answers  this  purpose.  By  carefully 


CHEMICAL  KELATIONS  OF  THE  METALS. 


39 


mixing  2  parts  by  weight  of  hydrochloric  acid  and  1  part  by 
weight  of  nitric  acid  a  mixture  known  as  aqua  regia  is  obtained. 
By  placing  gold  or  platinum  in  this  mixture  a  portion  of  the  oxygen 
of  the  nitric  acid  combines  with  the  hydrogen  of  the  hydrochloric 
acid  to  water,  whilst  the  chlorine  of  the  hydrochloric  acid  com¬ 
bines  with  the  metal  to  chloride  of  gold  or  chloride  of  platinum. 
The  nitric  acid,  deprived  of  a  portion  of  its  oxygen,  becomes 
nitrous  gas  and  nitrous  acid,  both  of  which  escape  as  yellow  vapors, 
very  injurious  to  the  respiratory  organs. 

The  combinations  of  silver  and  lead  with  chlorine  are  insoluble 
in  water.  Hence  hydrochloric  acid  does  not  dissolve  these  metals, 
a  superficial  layer  of  chloride  of  silver  or  chloride  of  lead  being 
formed,  which  prevents  the  further  action  of  the  acid. 

Combinations  of  the  Metals  with  Sulphur. — Sulphur  is  a  non- 
metallic  body  of  yellow  color,  which  melts  at  2220  F.  and  boils  at 
784°  F.,  whereby  it  is  converted  into  brown-red  vapors  which, 
when  sufficiently  cooled,  condense  to  a  yellow  powder  (flowers  of 
sulphur).  Sulphur  is  frequently  associated  with  metals,  a  large 
portion  of  the  latter  being  gained  from  metallic  sulphides. 

By  holding  a  piece  of  sheet  copper  in  the  brown-red  vapor  of 
sulphur  it  loses  its  flexibility  and  red  color  ;  it  becomes  brittle  and 
gray ;  jt  has  lost  25  per  cent,  of  weight  and  has  been  converted 
into  cuprous  sulphide,  which  consists  of  16  parts  sulphur  and  63.4 
parts  copper.  (There  is  also  a  combination  of  copper  with  sul¬ 
phur  which  contains  about  33^  per  cent,  of  sulphur.) 

By  wrapping  in  a  piece  of  tin-foil  one-half  of  its  weight  of  sul¬ 
phur  and  heating  them  in  a  test  cube  over  a  spirit  flame,  a  portion  of 
the  sulphur  evaporates,  while  another  portion  combines  with  the 
tin  to  brown-black  sulphide  of  tin,  which  consists  of  32  parts  sulphur 
and  1 18  parts  tin.  The  preparation  of  the  combination  of  sulphur 
with  tin  known  as  mosaic  gold  (59  parts  tin,  32  sulphur)  will  be 
given  later  on. 

With  iron  sulphur  combines  without  the  assistance  of  heat.  By 
mixing  30  parts  by  weight  of  iron  filings,  20  of  flowers  of  sulphur 
and  20  of  water  in  a  small  pot  and  placing  the  mixture  in  a  warm 
place  in  order  to  allow  the  water  to  evaporate,  a  black  powder  will 


40 


THE  METAL  WORKER’S  HANDY-COOK. 


be  found  in  the  pot  ;  this  powder  is  ferrous  sulphide  and  contains 
32  parts  sulphur  to  56  parts  iron. 

A  combination  containing  56  parts  iron  and  64  parts  sulphur  oc¬ 
curs  naturally  and  is  known  as  iron-pyrites. 

Metallic  sulphides  are  mostly  distinguished  by  a  characteristic 
coloration,  those  known  as  “  pyrites  ”  especially  having  a  beautiful 
gold  lustre. 

Laws  of  Combination  of  the  Elements. — In  the  preceding  para¬ 
graphs  the  phenomena  have  been  explained  by  which  from  two 
simple  bodies  a  new  body  with  new  properties  may  be  formed.  In 
the  following  the  opposite  case  will  be  considered,  because  many 
of  the  bodies  thus  formed  can  be  again  decomposed  into  their  con¬ 
stituents.  The  bodies  which  cannot  be  further  decomposed  either 
by  chemical  or  mechanical  means  are  called  elements. 

Table  of  the  Most  Important  Elements,  with  their  Sym¬ 
bols  and  Atomic  W eights  : 


Name. 


Aluminium . 

Antimony  (Stibium) .  . 

Arsenic . 

Barium . 

Bismuth . 

Boron . 

Bromine . 

Cadmium . 

Calcium . 

Carbon . 

Chlorine . 

Cohalt . 

Copper  (Cuprum) . 

Fluorine . 

Gold  (Aurum) . 

Hydrogen . 

Iodine . 

Iridium . 

Iron  (Ferrum) . 

Lead  (Plumbum) . 

Magnesium . 


Symbol. 

Atomic 

1  weight. 

Name. 

Symbol. 

Atomic 

weight. 

A1 

27.4 

Manganese . 

Mn 

55 

Sb 

I  22 

Mercury  (Hydrargy- 

As 

75 

rum) . 

Hg 

200 

Ba 

137 

Nickel . 

Ni 

58.8 

Bi 

210 

Nitrogen . 

N 

14 

B 

I  I 

Oxygen . 

O 

l6 

Br 

80 

Palladium . 

Pd 

106.6 

Cd 

I  12 

Phosphorus . 

P 

31 

Ca 

40 

Platinum . 

Pt 

197-4 

c 

12 

Potassium  (Kalium).. . 

K 

39-i 

Cl 

35-5 

Selenium . 

Se 

79-4 

Co 

58.8 

Silicium . 

Si 

28 

Cu 

634 

Silver  (Argentum) .... 

Ag 

108 

F 

>9 

Sodium  (Natrium) . 

Na 

23 

Au 

197 

Sulphur . 

S 

32 

II 

I 

Thallium . 

T1 

204 

I 

127 

Tin  (Stannum) . 

Sn 

118 

Ir 

198 

Titanium . 

Ti 

50 

Fe 

56 

Tungsten  or  Wolfram 

W 

184 

Pb 

207 

Uranium . 

U 

240 

Mg 

24 

Zinc . 

Zn 

65.2 

CHEMICAL  RELATIONS  OF  THE  METALS. 


41 


The  names  of  the  most  important  elements  are  given  in  the  fore¬ 
going  table.  Opposite  to  them  in  the  third  column  are  placed 
certain  numbers  which  express  the  proportions  in  which  they  com¬ 
bine  together  or  simple  multiples  of  those  proportions;  these  num¬ 
bers  are  called  atomic  or  indivisible  weights.  In  the  second  column 
are  placed  symbols  by  which  these  weights  are  denoted  ;  these  sym¬ 
bols  are  formed  of  the  first  letters  of  the  Latin  names  of  the  ele¬ 
ments,  a  second  letter  being  added  when  the  names  of  two  or  more 
elements  begin  with  the  same  letter.  The  names  of  the  metallic 
elements  are  distinguished  by  large  type. 

From  the  table  it  will  be  seen  that,  for  instance,  118  parts 
of  tin  combine  with  32  parts  of  sulphur,  or  with  16  parts  of  oxy¬ 
gen.  The  elements  combine,  however,  not  only  according  to  the 
proportion  of  their  atomic  weights,  but  also  according  to  the  mul¬ 
tiples  thereof.  On  p.  39  was  mentioned  a  combination  of  tin  and 
sulphur,  consisting  of  118  parts  tin  and  (2  X  32  =)  64  parts  of 
sulphur,  and  tin-stone  contains  for  118  parts  of  tin  (2  X  16  =)  32 
parts  of  oxygen. 

As  previously  stated,  each  chemical  element  is  denoted,  for 
brevity’s  sake,  by  a  symbol,  which  also  expresses  the  atomic  weight. 
Hg,  for  instance,  does  not  only  mean  mercury,  but  also  200  parts 
by  weight  of  mercury.  To  express  chemical  combinations,  the 
symbols  of  the  elements  are  placed  along-side  each  other,  thus : 

Hg  S  =  (mercury  and  sulphur  =)  cinnabar. 

Cl  H  =  (chlorine  and  hydrogen  =)  hydrochloric  acid. 

If  in  the  combination  one  of  the  elements  is  contained  as  a  mul¬ 
tiple,  a  small  figure  denoting  the  multiple  is  placed  at  the  right  of 
the  symbol.  Thus  the  symbol 

For  Ferric  chloride  is  Fe  Cl3 
“  Minium  “  Pb3  04 

“  Cuprous  oxide  “  Cu2  O 
“  Nitric  acid  “  FI  N  03 

Metallic  Salts. — As  previously  mentioned  the  combinations  of 
the  metals  with  oxygen  differ  essentially  from  those  of  the  non- 


42 


THE  METAL  WORKER’S  HANDY-BOOK. 


metals  with  oxygen.  While  the  first,  when  soluble  in  water,  have 
an  alkaline  taste,  the  latter  have  an  acid  taste ;  the  first  are  called 
bases  and  the  latter  acids. 

Blue  litmus-tincture  is  an  infallible  reagent  for  acids ;  a  drop  of 
it  brought  into  an  acid  fluid  is  colored  red.  The  tincture  is  pre¬ 
pared  by  pouring  over  commercial  litmus  ten  times  its  weight  of 
water  and  letting  it  stand  for  12  hours.  The  fluid  is  then  decanted 
from  the  sediment  and  kept  for  use  in  a  wide-mouthed,  open  bottle. 
In  a  corked  bottle  it  soon  decomposes. 

To  make  litmus-tincture  available  for  the  detection  of  alkalies, 
compound  it  drop  by  drop  with  dilute  hydrochloric  acid  until  it 
becomes  red.  Red  litmus-tincture  is  colored  blue  by  an  alkaline  fluid. 

For  many  purposes  it  is  of  advantage  to  use  litmus-paper  in  place 
of  the  tincture,  the  fluids  to  be  tested  not  being  colored  by  it.-  It 
is  prepared  by  soaking  filtering  paper  in  litmus-tincture,  drying 
and  cutting  it  into  small  pieces  ;  one-half  of  each  piece  is  finally 
drawn  through  dilute  hydrochloric  acid,  the  red  portion  serving  as 
a  reagent  for  alkalies,  and  the  blue  for  acids. 

In  the  same  manner  as  the  elements  combine  together  the  bases 
may  also  enter  into  combinations  with  the  acids.  Such  combina¬ 
tions  are  called  salts  and  are  generally  distinguished  by  the  ap¬ 
pearance  of  characteristic  crystalline  forms. 

By  dissolving  black  oxide  of  copper  in  hydrochloric  acid  a  blue 
solution  is  obtained  from  which  a  blue  salt  crystallizes  out.  This 
salt  is  cupric  sulphate  or  blue  vitriol. 

Litharge  dissolved  in  acetic  acid  gives  acetate  of  lead  or  sugar  of 
lead,  which  crystallizes  out  in  transparent  colorless  crystals. 

By  treating  metals  with  acids,  salts  are  also  formed,  but  the 
metals  must  first  be  oxidized  before  being  brought  in  contact  with 
the  acid.  By  pouring,  for  instance,  dilute  sulphuric  acid  over 
zinc,  the  latter  withdraws  the  oxygen  from  the  water  while  the  hy¬ 
drogen  escapes.  In  dissolving  silver  in  nitric  acid  the  silver  with¬ 
draws  from  the  acid  a  portion  of  its  oxygen  and  the  acid  becomes 
nitrous  oxide,  which  on  coming  in  contact  with  the  air  is  com 
verted  into  nitrous  acid.  The  same  phenomena  appear  in  dissolv¬ 
ing  copper  as  well  as  other  metals  in  nitric  acid. 


CHEMICAL  RELATIONS  OF  THE  METALS 


43 


Metallic  oxides  being  thus  formed  they  may  combine  with  the 
respective  acids,  the  result  being  sulphate  of  zinc,  or  nitrate  of 
silver,  or  nitrate  of  copper.  It  will,  however,  readily  be  seen  that 
the  gaining  of  nitrates  directly  from  the  metals  cannot  be  profit¬ 
able,  since  a  portion  of  the  acid  is  consumed  for  the  oxidation  of 
the  metal. 

By  treating  metals  with  hydrochloric  acid  metallic  chlorides  are 
formed  (see  page  36).  In  the  metallic  chlorides  the  acid,  how¬ 
ever,  is  not  combined  with  a  base,  though  generally  they  have  the 
character  of  a  salt.  To  distinguish  them  and  the  combinations  of 
the  metals  with  iodine  and  bromine  from  the  combinations  with 
oxygen,  the  term  haloid  salts  is  applied  to  them. 

All  the  salts  mentioned  thus  far  are  soluble  in  water ;  insoluble 
in  water  or  soluble  with  difficulty  are,  for  instance,  the  salts  of 
barium,  strontium,  calcium  and  lead  obtained  with  sulphuric, 
chromic  and  sulphurous  acids  and  the  haloid  salts  of  lead,  silver,  etc. 

These  salts  may  be  obtained  by  two  different  methods :  either 
by  compounding  a  soluble  salt  with  the  respective  acid  or  by  mix¬ 
ing  the  solutions  of  two  salts  which  reciprocally  exchange  their 
constituents'. 

By  compounding  a  solution  of  sugar  of  lead  with  tartaric  acid 
tartrate  of  lead  is  precipitated,  whilst  the  supernatant  liquid  con¬ 
tains  acetic  acid.  By  adding  hydrochloric  acid  to  a  solution  of 
nitrate  of  silver,  chloride  of  silver  is  precipitated,  the  supernatant 
fluid  containing  nitric  acid.  If  the  solution  of  nitrate  of  silver  be 
compounded  with  sodium  chloride  (common  salt)  chloride  of  sil¬ 
ver  is  also  precipitated,  but  the  nitric  acid  liberated  from  the 
nitrate  of  silver  combines  with  the  sodium  to  a  salt. 

From  a  solution  of  sugar  of  lead  compounded  with  a  solution 
of  potassium  bichromate,  chromate  of  lead,  the  chrome-yellow  of  the 
painter,  is  separated,  the  acetic  acid  of  the  sugar  of  lead  being  re¬ 
placed  by  the  chromic  acid  of  the  potassium  bichromate.  In  a 
similar  manner  metallic  sulphides  can  be  precipitated  from  the 
solutions  of  metallic  salts,  sulphuretted  hydrogen  being  used  for 
the  purpose. 

Precipitates  with  Sulphuretted  Hydrogen. — For  the  preparation  of 


44 


THE  METAL  WORKER’S  HANDY-BOOK. 


sulphuretted  hydrogen  the  apparatus  shown  in  Fig.  2  may  be  used. 
It  consists  of  the  developing  vessel  a ,  a  porcelain  sieve  b,  suspended 
by  means  of  a  platinum  wire  to  a  glass  rod,  a  funnel  c  and  a  bent 
tube,  to  which  is  secured  a  second  tube  by  means  of  a  rubber 
hose.  By  the  clip  d  the  gas  developed  in  the  glass  vessel  may  be 
shut  off.  The  porcelain  sieve  is  filled  with  small  pieces  of  iron 
monosulphide  and  dilute  sulphuric  acid  (1  part  acid  to  5  water) 
poured  in  through  the  funnel  until  a  copious  disengagement  of  gas 
takes  place.  Sulphuretted  hydrogen  is  a  colorless  gas  having  the 


Fig.  2. 


odor  of  putrid  eggs;  it  is  not  an  irritant,  but,  on  the  contrary, 
powerfully  narcotic.  Water  absorbs  it  with  avidity.  It  has  the 
property  of  decomposing  the  oxides  of  heavy  metals  and  precipi¬ 
tating  the  metals  as  metallic  sulphides.  The  precipitate  has  generally 
a  characteristic  color.  In  the  presence  of  antimony  it  is  orange  ; 
of  cadmium,  arsenic  or  stannic  oxide,  yellow  ;  of  bismuth  or  stan¬ 
nous  oxide,  brown ;  of  gold,  brown-black ;  of  silver,  lead  or 
gold,  black. 

If  zinc,  nickel,  iron  or  cobalt  be  present  in  the  solution,  the  lat¬ 
ter  must  first  be  made  alkaline,  the  combinations  of  these  metals 
with  sulphur  being  soluble  in  dilute  acids.  To  make  the  solutions 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


45 


alkaline  compound  them  with  ammonia  until  red  litmus  paper  be¬ 
comes  blue.  From  the  alkaline  solution  sulphuretted  hydrogen 
precipitates  zinc  with  a  white  color,  manganese  with  a  flesh  color, 
and  iron,  nickel  and  cobalt  with  a  black  color. 


II. 

THE  MOST  IMPORTANT  METALLIC  PREPARATIONS,  AND 
THE  CHEMICALS  USED  IN  THE  METAL-INDUSTRY. 

i.  Iron  Preparations. 

Ferrous  sulphate  ( copperas ,  green  vitriol )  is  obtained  in  pale 
green  crystals  which  rapidly  oxidize  in  the  air.  It  is  best  prepared 
by  dissolving  iron  filings  in  dilute  sulphuric  acid  and  filtering  the 
boiling  hot  solution.  By  mixing  the  filtrate  with  spirit  of  wine  the 
ferrous  sulphate  separates  as  a  fine  white  crystalline  meal  which  is 
washed  with  spirit  of  wine  and  quickly  dried  between  blotting- 
paper.  Ferrous  sulphate  thus  prepared  is  distinguished  by  great 
durability,  whilst  the  commercial  article,  which  is  mostly  prepared 
from  iron  pyrites,  quickly  oxidizes  in  the  air  and  gives  turbid 
solutions. 

A7nmonio-ferrous  sulphate  is  formed  by  dissolving  separately  in  as 
little  water  as  possible,  139  parts  of  ferrous  sulphate  and  60  of 
ammonium  sulphate,  and  pouring  the  solutions  heated  to  140°  F. 
into  a  porcelain  dish,  adding  a  few  drops  of  sulphuric  acid  and 
stirring  until  cool.  A  pale  blue  crystalline  meal  is  deposited  which 
the  next  day  is  dried  in  a  funnel,  the  tube  of  which  is  closed  by 
a  tuft  of  cotton. 

Ferrous  chloride  is  obtained  by  dissolving  iron  in  hydrochloric 
acid.  By  sufficiently  evaporating  the  solution  pale  green  crystals 
are  obtained  which  readily  oxidize  in  the  air  and  dissolve  with  ease 
in  spirit  of  wine. 

Ferric  chloride  is  obtained  as  a  black-brown  hygroscopic  mass 
by  adding  chlorine  water  to  a  solution  of  ferrous  chloride,  or  by 


46 


THE  METAL  WORKER’S  IIANDY-BOOK. 


dissolving  ferric  oxide  in  hydrochloric  acid.  In  water  it  dissolves 
to  a  yellow  fluid. 

Sesquioxide  of  iron ,  colcothar  or  rouge  occurs  in  commerce  as  a 
brown-red  powder.  It  is  obtained  as  a  by-product  in  the  manu¬ 
facture  of  sulphuric  acid  from  solution  of  ferrous  sulphate.  A 
product  of  a  red-brown  color  consisting  of  sesquioxide  of  iron  and 
clay  has  recently  been  brought  into  commerce  under  the  name  of 
iron  minium ;  it  is  used  in  the  preparation  of  paint. 

Potassium  ferrocyanide  ( yellow  prussiate  of  potash)  is  a  commer¬ 
cial  article.  It  occurs  in  the  shape  of  fine  yellow  and  semi-trans- 
lucenf  crystals  with  mother-of-pearl  lustre,  which  break  gradually 
and  without  noise.  The  fracture  is  jagged,  and  filled  with  a  multi¬ 
tude  of  small  bright  spots. 

Potassium  ferricyanide  ( red  prussiate  of  potash)  is  obtained  by 
allowing  chlorine  to  act  upon  a  solution  of  yellow  prussiate  of 
potash.  It  forms  prismatic  or  sometimes  tabular  crystals.  It 
serves  for  distinguishing  ferric  from  ferrous  oxides,  its  solution 
yielding  a  deep  blue  precipitate  with  ferrous  oxides,  but  not  with 
ferric  oxides. 

Ferric  sulphate'  is  obtained  by  heating  5  parts  of  ferrous  sulphate 
with  15  parts  of  water  and  1  part  of  sulphuric  acid,  and  adding  to 
the  boiling  solution  nitric  acid  in  small  quantities  until  the,  at  first 
black,  fluid  has  acquired  a  brown-yellow  color.  By  evaporation  it 
yields  a  pale  yellow  crystalline  mass,  from  which  anhydrous  ferric 
sulphate  is  obtained  by  compounding  the  concentrated  solution 
with  sulphuric  acid.  With  yellow  prussiate  of  potash  ferric  sul¬ 
phate  gives  a  deep  blue  precipitate  which  is  know  as  Berlin  blue. 
By  mixing  solution  of  ferrous  sulphate  with  solution  of  yellow 
prussiate  of  potash  a  pale  blue  precipitate — protocyanide  of  iron — ■ 
is  obtained,  which  after  long  standing  in  the  air  is  also  converted 
into  Berlin  blue. 

2.  Preparations  of  Cobalt  and  Nickel. 

Cobaltous  chloride  is  obtained  in  blue  crystalline  scales  of  a 
greasy  touch  by  heating  the  metal  in  chlorine,  or  by  adding  strong 
hydrochloric  acid  to  a  solution  of  the  protoxide  in  hydrochloric 


MOST  IMPORTANT  METALLIC  PREPARATIONS.  47 

» 

acid.  By  absorption  of  water  the  color  of  the  scales  changes  to 
red. 

Cobaltous  nitrate  is  a  red  crystalline  salt  and  very  deliquescent. 
By  prolonged  heating  the  acid  escapes  and  steel-blue  sesquioxide 
of  cobalt  remains  behind. 

Cobaltous  oxide  is  a  greenish-gray  powder  readily  reduced  to  the 
metallic  state  by  ignition  in  hydrogen,  and  is  converted  into  the 
sesquioxide  in  presence  of  oxygen. 

Nickel  chloride  is  best  obtained  by  dissolving  metallic  nickel  in 
aqua  regia.  A  solution  of  nickel  or  its  oxide  in  hydrochloric  acid 
also  yields,  after  evaporation,  nickel  chloride  in  small  granular 
crystals  of  a  blue  color,  which  dissolve  in  water  with  a  green,  and 
in  ammonia,  with  a  blue  color.  In  the  dry  way  it  is  obtained  in 
delicate,  lardaceous  scales  by  conducting  chlorine  gas  over  slightly 
heated  metallic  nickel. 

Nickel  sulphate  is  obtained  by  dissolving  metallic  nickel  in  sul¬ 
phuric  acid  compounded  with  a  few  drops  of  nitric  acid  to  accel¬ 
erate  the  action.  It  crystallizes  out  in  emerald-green  crystals 
which  readily  dissolve  in  water,  and  with  spirit  of  sal-ammoniac, 
give  a  dark  blue  fluid. 

Nickel  nitrate  is  an  emerald-green  powder,  also  soluble  in  am¬ 
monia  ;  it  is  very  deliquescent.  It  is  obtained  by  dissolving 
metallic  nickel  in  nitric  acid. 

By  adding  potash  or  soda  to  a  solution  of  a  nickel  salt,  nickel 
hydrate  is  precipitated  as  a  green  powder.  It  is  soluble  in  am¬ 
monia,  forming  a  violet  solution. 

3.  Copper  Preparations. 

Copper-powder  used  in  the  preparation  of  copper  amalgam  is  pre¬ 
pared  as  follows:  Place  a  strip  of  sheet-zinc  in  a  saturated  solution 
of  blue  vitriol  mixed  with  an  equal  volume  of  hydrochloric  acid. 
The  copper  is  precipitated  as  a  fine  powder  which,  after  decanting 
the  supernatant  fluid,  is  washed  first  with  weak  and  next  with 
stronger  alcohol ;  it  is  then  quickly  dried  to  prevent  oxidation. 

Cupric  sulphate  (sulphate  of  copper,  blue  vitriol )  is  the  best  known 
copper  salt.  It  occurs  in  blue  crystals  and  dissolves  in  4  parts  of 


48 


TI1E  METAL  WORKER’S  HANDY-BOOK. 


cold  water.  It  is  obtained  by  dissolving  cupric  oxide  in  sulphuric 
acid,  or  on  the  large  scale,  by  heating  scrap  or  refuse  copper  with 
sulphur  in  a  furnace  so  as  to  convert  it  into  cuprous  sulphide  which 
is  then  oxidized  to  cupric  sulphate  and  oxide.  The  mass  is  thrown 
into  dilute  sulphuric  acid  and  the  resulting  sulphate  crystallizes  out 
from  the  solution. 

Cupro-diammonium  sulphate. — By  adding  ammonia  to  a  solution 
of  cupric  sulphate  a  pale  blue  precipitate  is  formed  which,  by  a 
further  addition  of  ammonia,  dissolves  to  a  dark  blue  fluid.  By 
carefully  adding  to  the  fluid  double  its  volume  of  alcohol  the  cupro- 
diammonium  sulphate  crystallizes  out  after  24  hours. 

Copper  nitrate  is  formed  by  dissolving  the  metal  or  oxide  in 
nitric  acid  and  concentrating  the  solution  in  a  copper  kettle.  It 
forms  dark  blue,  prismatic  crystals. 

Cupric  chloride. — This  salt  is  obtained  in  long  bluish-green 
needles  by  dissolving  cupric  oxide  in  hydrochloric  acid  and  evap¬ 
orating  the  solution.  By  heating  the  needles  water  escapes,  then 
chlorine,  while  cuprous  chloride  remains  behind.  On  exposure  to  the 
sun  it  acquires  a  copper  color  and  a  metallic  lustre.  It  is  also 
obtained  as  a  brown  fluid  by  heating  solution  of  cupric  chloride 
compounded  with  hydrochloric  acid  together  with  copper.  By  the 
addition  of  water  the  cuprous  chloride  precipitates  as  a  white 
powder. 

In  a  cold  solution  of  sodium  hyposulphite  cuprous  chloride  dis¬ 
solves  to  a  yellow  fluid,  which  does  not  change  at  an  ordinary 
temperature,  but,  when  heated,  deposits  black  sulphide  of  copper. 
Sulphide  of  copper  with  a  black  color  is  also  precipitated  by 
sulphuretted  hydrogen  from  solutions  of  copper  salts. 

Copper  carbonate. — On  adding  a  solution  of  soda  to  one  of 
cupric  sulphate  a  pale  blue  precipitate  of  copper  carbonate  is 
formed  which  after  some  time  becomes  green ;  it  is  known  under 
the  name  of  mmeral  green. 

Acetate  of  copper  occurs  in  two  varieties : 

1.  The  tieu/ral  salt  obtained  by  dissolving  cupric  oxide  in  acetic 
acid.  It  is  found  in  the  market  either  in  the  form  of  dark  green 
crystals  or  of  a  bright  green  powder — highly  poisonous — soluble  in 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


49 


water  which  becomes  green  ;  very  soluble  in  ammonia,  forming  a 
solution  of  an  azure-blue  color.  . 

2.  The  basic  salt  or  verdigris ;  it  is  a  powder  of  a  fine  turquois 
bluish-green;  it  is  highly  poisonous.  It  is  obtained  either  from 
copper  and  vinegar  (German  verdigris),  or  by  piling  together 
sheets  of  copper  with  the  skins  of  pressed  grapes  (French  verdi¬ 
gris).  It  is  imperfectly  soluble  in  water,  and  difficult  to  combine 
with  the  sulphites  and  cyanides,  unless  previously  treated  with 
ammonia.  It  is  often  used  for  adulterating  the  neutral  salt. 

Cyanide  of  copper. — Two  salts  are  called  by  this  name  ;  one  im¬ 
properly  so  called  is  the  ferrocyanide,  a  powder  of  a  maroon  or 
Vandyke-brown  color,  obtained  by  the  precipitation  of  a  soluble 
copper  salt  with  ferrocyanide  of  potassium ;  the  other,  the  cyanide, 
a  dirty  white  powder  with  a  greenish-yellow  tinge  resulting  from 
the  precipitation  of  a  soluble  copper  salt  by  cyanide  of  potassium. 
Whatever  be  its  mode  of  production,  it  is  freely  soluble  in  all  the 
alkaline  cyanides. 

Cupric  and  cuprous  oxides. — The  formation  of  these  oxides  has 
already  been  discussed  on  page  35.  Cuprous  oxide  is  soluble  in 
ammonia.  Th®  ammoniacal  copper  compound  formed  is  a  very 
strong  reducing  agent,  and  serves  for  the  precipitation  of  silver  in 
the  manufacture  of  silver  mirrors. 

4.  Preparations  of  Lead,  Tin  and  Bismuth. 

Acetate  of  lead  ( sugar  of  lead)  is  a  poisonous  salt  obtained  by 
dissolving  litharge  in  acetic  acid  and  evaporating  the  solution.  It 
is  ordinarily  found  in  the  shape  of  crystalline  masses;  white; 
light;  very  soluble;  savor,  at  first  sweetish,  then  metallic.  It 
yields  a  turbid  solution  which  becomes  clear  by  the  addition  of  a 
few  drops  of  acetic  acid. 

Lead  carbonate  ( white  lead )  is  used  as  a  paint ;  insoluble  in 
water. 

Lead  chloride  is  readily  obtained  by  adding  hydrochloric  acid  or 
a  soluble  chloride  to  a  solution  of  a  lead  salt.  It  crystallizes  in 
white  lustrous  needles,  sparingly  soluble  in  cold  water  (1  part  in 
4 


50 


TOE  METAL  WORKER’S  HANDY-BOOK. 


1 20),  but  much  more  soluble  in  boiling  water  and  in  strong 
hydrochloric  acid. 

Lead  sulphate  is  formed  as  a  precipitate  insoluble  in  water  by 
mixing  solution  of  a  lead  salt  and  sulphuric  acid. 

Lead  chromate  ( chrome  yellow). — This  salt  is  obtained  as  a 
brilliant  yellow  precipitate  on  mixing  solutions  of  potassium 
chromate  or  dichromate  with  lead  nitrate  or  acetate.  On  boiling 
it  with  lime  water,  one-half  of  the  acid  is  withdrawn,  and  a  basic 
lead  chromate  of  an  orange-red  color  left. 

Stannous  chloride  (. Protochloride  of  tin ,  Tin-salt). — This  salt  is 
manufactured  in  large  quantities,  and  occurs  in  commerce  in  the 
form  of  small,  needle-like  crystals.  It  is  greasy  to  the  touch, 
fuses  readily,  communicates  to  the  fingers  a  characteristic  odor  and 
has  a  taste  at  first  saline  and  then  astringent  and  caustic.  It  is 
soluble  in  water,  but  is  partly  precipitated  in  the  state  of  a  white 
subsalt,  which  readily  dissolves  in  a  slight  excess  of  acid. 

Stannous  chloride  is  prepared  by  dissolving  granulated  tin  (in 
excess)  in  hot  hydrochloric  acid,  evaporating  the  solution  to  a 
syrupy  consistency  and  letting  it  crystallize.  When  the  crystals 
are  heated  they  first  fuse  in  their  water  of  crystallization,  which 
soon  evaporates,  carrying  off  a  small  portion  of  hydrochloric  acid. 
The  operation  is  completed  when  thick  white  fumes  begin  to  be 
evolved,  which  is  evidence  that  the  salt  itself  is  beginning  to 
volatilize.  The  fused  chloride  of  tin  thus  obtained  is  preferable 
for  tinning  with  alkaline  baths. 

Stannic  sulphide  may  be  obtained  in  golden  yellow  spangles  by 
passing  stannic  chloride  and  sulphuretted  hydrogen  through  a 
heated  tube,  or  by  heating  mixtures  of  finely-divided  tin,  sulphur 
and  sal-ammoniac,  or  of  stannous  sulphide  and  corrosive  sublimate. 
The  preparations  thus  obtained  are  known  under  the  name  of 
mosaic  gold. 

Bismuth  Jiitrate  forms  transparent  crystals,  and  is  obtained  by 
dissolving  bismuth  in  nitric  acid.  The  crystals  are  decomposed  by 
water  with  the  production  of  a  basic  salt. 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


51 


5.  Preparations  of  Zinc,  Antimony  and  Arsenic. 

Chloride  of  zinc  is  obtained  in  solution  by  introducing  zinc  into 
hydrochloric  acid  until  a  portion  of  it  remains  undissolved. 

Zinc  sulphate  (white  vitriol)  is  obtained  on  a  large  scale  by 
roasting  blende  and  lixiviating  the  roasted  mass  with  water.  In 
commerce  it  is  found  in  three  forms  :  either  in  white  or  opaque 
plates,  or  in  large  transparent  crystals,  or  in  a  mass  formed  of  a 
quantity  of  needle-like  crystals  resembling  those  of  tin-salt.  Its 
taste  is  sour,  styptic  and  metallic,  and  it  is  very  soluble  in  water, 
which  remains  colorless. 

Zinc  oxide  prepared  by  burning  the  metal  is  employed  as  a 
pigment  under  the  name  of  zinc  white ;  it  is  chiefly  valued  for  its 
permanency,  as  it  is  not  blackened  by  exposure  to  sulphuretted 
hydrogen  like  white  lead. 

Iron  black  is  finely  divided  antimony  powder  precipitated  from 
a  solution  of  antimony  by  zinc.  It  imparts  to  figures  of  plaster  of 
Paris  and  papier-machd  the  appearance  of  bright  steel ;  hence  its 
name. 

Antimony  trichloride  is  obtained  by  the  action  of  chlorine  or 
mercuric  chloride  upon  the  metal  or  by  heating  the  trisulphide  with 
mercuric  chloride.  It  is  a  translucent,  light  yellow  fatty  mass, 
whence  its  common  name  of  butter  of  antimony.  On  exposure  to 
the  air  it  absorbs  water  with  avidity,  forming  a  very  caustic  fuming 
liquid.  An  addition  of  water  causes  turbidity  and  precipitation ; 
hence  it  is  diluted  with  alcohol. 

Tartar  ejnetic. — By  boiling  the  tetroxide  of  antimony  with 
cream  of  tartar  it  is  dissolved  and  the  solution  yields  on  evapora¬ 
tion  crystals  of  tartar  emetic,  which  is  almost  the  only  antimonious 
salt  which  will  bear  admixture  with  water  without  decomposition. 
In  the  metal  industry  it  is  used  for  the  production  of  lustrous 
colors  upon  brass. 

White  arsenic  or  arsenious  acid,  a  very  poisonous  substance, 
which  generally  occurs  in  the  shape  of  a  white  powder  and  some¬ 
times  in  vitreous-like  lumps  resembling  porcelain.  It  is  slightly 


62 


THE  METAL  WORKER’S  HANDY-BOOK. 


soluble  in  water.  It  is  employed  in  certain  silver-whitening  baths 
and  also  in  the  electro-baths  for  brass. 

Schweinfurt  green  is  obtained  from  equal  parts  of  arsenious  acid 
and  neutral  verdigris  by  heating  the  solutions  by  themselves  and 
mixing  them  boiling  hot.  It  consists  of  31.29  parts  cupric  oxide, 
58.65  arsenious  acid  and  10.6  acetic  acid.  It  is  very  poisonous. 

6.  Preparations  of  Mercury  and  Silver. 

Mercurous  sulphate  is  a  white,  sparingly  soluble,  crystalline 
powder,  formed  by  slightly  heating  mercury  with  concentrated 
sulphuric  acid. 

Mercuric  nitrate  is  obtained  by  dissolving  at  a  gentle  heat  mer¬ 
cury  in  nitric  acid  and,  when  solution  is  complete,  boiling  the 
fluid  for  a  few  minutes. 

Mercurous  nitrate  is  a  white  crystalline  salt,  obtained  by  dissolv¬ 
ing  the  metal  in  cold  dilute  nitric  acid.  Potash  solution  precipi¬ 
tates  from  the  solution  mercurous  oxide,  which  is  readily  resolved 
on  exposure  to  light  or  by  simple  trituration  in  a  mortar  into  mer¬ 
cury  and  mercuric  oxide. 

Mercuric  chloride  or  corrosive  sublimate  is  obtained  by  dissolving 
the  metal  in  aqua  regia.  It  crystallizes  out  in  the  form  of  white 
columns  ;  it  is  highly  poisonous. 

Nitrate  of  silver  (. silver  nitrate,  lunar  caustic)  is  one  of  the  most 
important  silver  salts.  It  is  readily  made  by  dissolving  the  metal 
in  moderately  dilute  nitric  acid  and  concentrating  the  solution 
when  it  separates  out  in  anhydrous  tables.  In  the  trade  the  salt  is 
found  in  three  forms:  either  as  crystallized  nitrate  of  silver  in  thin 
rhombic  and  transparent  plates ;  or  in  amorphous,  opaque  and 
white  plates  of  fused  nitrate;  or  in  small  cylinders  of  white,  or 
gray,  or  black  color,  according  to  the  nature  of  the  mould  em¬ 
ployed,  in  which  form  it  constitutes  the  lunar  caustic  for  surgical 
uses. 

Nitrate  of  silver  dissolves  in  its  own  weight  of  water,  forming  a 
neutral  solution,  which  is  partially  reduced  by  the  action  of  hydro¬ 
gen  with  the  production  of  silver  and  silver  nitrate.  In  the  metal 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


53 


industry  it  is  employed  for  preparing  silver-baths,  metallizing 
moulds  and  for  many  other  purposes. 

Chloride  of  silver  ( argentic  chloride ,  hor-n  silver )  is  readily  ob¬ 
tained  by  adding  hydrochloric  acid  or  a  chloride  to  a  solution  of 
nitrate  of  silver.  It  forms  a  white  curdy  mass  almost  absolutely 
insoluble  in  water.  On  exposure  to  the  light  it  soon  turns  blue 
and  then  black.  To  prevent  this  decomposition  it  should  be  kept 
in  blue  or  opaque  bottles.  It  fuses  at  a  high  temperature  and  ac¬ 
quires  the  appearance  of  horn,  from  which  it  derives  its  name  of 
horn  silver.  It  is  employed  in  the  preparation  of  the  baths  for 
electro-silvering,  for  the  whitening  baths  and  for  the  pastes  for 
silvering  by  friction.  It  readily  dissolves  in  ammonia. 

Argentic  oxide  is  precipitated  as  a  black  powder  from  a  solution 
of  nitrate  of  silver  by  ammonia.  It  is  redissolved  by  an  excess  of 
the  precipitating  agent. 

Silver  carbonate  is  insoluble  in  water  and  is  formed  as  a  precipi¬ 
tate  on  bringing  together  solutions  of  nitrate  of  silver  and  of 
potash. 

Cyanide  of  silver  ( prussiate  or  hydrocyanate  of  silver). — This 
substance  is  white,  becomes  slowly  black  when  exposed  to  light 
and  is  insoluble  in  water  and  in  cold  acids,  which,  however,  will 
dissolve  it  with  the  aid  of  heat.  It  is  prepared  by  passing  cyano¬ 
gen  gas  through,  or  adding  hydrocyanic  acid  to,  a  cold  solution  of 
nitrate  of  silver.  The  precipitate  formed  is  thoroughly  washed 
and  kept  in  a  moist  condition  in  blue  or  black  bottles. 

Silver  sulphate  is  formed  by  the  action  of  hot  concentrated  sul¬ 
phuric  acid  on  the  metal,  or  by  adding  sulphuric  acid  to  a  strong 
solution  of  silver  nitrate.  It  is  sparingly  soluble  in  water  •  it  forms 
with  ammonia  a  readily  soluble  compound. 

Silver  sulphide  is  obtained  by  fusing  silver  with  sulphur.  It  is 
readily  fusible,  forming,  when  cold,  a  leaden-gray  mass,  which  is 
so  soft  that  it  may  be  readily  cut  with  a  knife  and  pressed  into 
moulds. 

Silver  hyposulphite  is  prepared  by  adding,  to  a  solution  of  nitrate 
of  silver,  ammonia  until  the  precipitate  is  dissolved  and  then  pour- 


54 


THE  METAL  WORKER’S  HANDY-BOOK. 


ing  in  a  concentrated  solution  of  sodium  hyposulphite  and  alcohol. 
The  salt  separated  is  washed  and  dried. 

7.  Preparations  of  Gold  and  Platinum. 

Chloride  of  gold  ( auric  chloride')  is  generally  prepared  by  dissolv¬ 
ing  finely  laminated  or  otherwise  comminuted  gold  in  aqua  regia. 
The  operation  is  conducted  in  a  glass  flask  and  with  the  aid  of  a 
gentle  heat  until  all  the  gold  has  dissolved  to  form  a  yellow  liquid, 
which  still  retains  a  great  excess  of  acid.  The  heat  is  then  slightly 
increased  and  continued  until  the  liquid  is  a  hyacinth-red.  After 
cooling  a  crystallized  mass  of  a  fine  yellow  color  is  obtained,  which 
is  well  adapted  to  the  preparation  of  the  immersion-gilding  bath. 

On  the  other  hand,  for  electro-gilding  baths,  the  action  of  the 
fire  should  preferably  be  continued  until  the  liquid  in  the  flask  has 
acquired  a  blackish-red  .color  without  losing  its  fluidity.  On 
cooling  the  crystals  are  brown-red. 

Aurous  chloride  is  a  yellowish-white  insoluble  powder,  obtained 
by  heating  auric  chloride  to  about  302°  F.  until  the  color  changes 
to  pure  yellow. 

Cyanide  of  gold  ( prussiate  or  hydrocyanate  of  gold)  is  prepared 
by  precipitating  a  solution  of  chloride  of  gold  with  a  solution  of 
cyanide  of  potassium.  An  excess  of  alkaline  cyanide  must  be 
avoided,  as  it  will  dissolve  the  precipitate  and  form  a  double 
cyanide  of  gold  and  potassium.  This  salt  is  employed  for  the 
preparation  of  gilding  baths  and  is  preferred  to  the  chloride  for 
this  purpose,  as  it  avoids  the  objection  of  introducing  chloride  of 
potassium  into  the  gilding  solution. 

Gold  salt  (  Gozzy's  gold  salt,  Sal  auri  Figuicri,  Aurum  muriati- 
cutn  natronatum  crystallisation). — Dissolve  8  parts  of  gold  in  aqua 
regia.  Add  2  parts  of  common  salt  and  evaporate  to  dryness.  Or 
dissolve  1  part  of  gold  in  a  mixture  of  4  parts  of  hydrochloric 
acid  and  1  of  nitric  acid,  evaporate  the  solution  to  crystallization, 
dissolve  it  in  8  parts  of  water,  mix  the  solution  with  o.  25  part  of 
common  salt  and  again  evaporate  to  crystallization.  In  the  pres¬ 
ence  of  free  acid  dissolve  the  mass  in  water,  evaporate  to  crystal¬ 
lization  and  recrystallize  several  times.  Or,  dissolve  100  parts  of 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


56 


gold  in  400  of  hydrochloric  acid  and  100  of  nitric  acid,  heat  until 
all  the  nitric  acid  is  decomposed,  then  mix  with  73  parts  of  sodium 
carbonate  and  evaporate  to  dryness.  (In  place  of  common  salt 
or  sodium  carbonate  potassium  chloride  or  potassium  carbonate 
may  be  used.) 

Purple  of  Cassius,  so  named  after  its  discoverer,  is  the  dark- 
purple  precipitate  formed  on  bringing  together  dilute  solution  of 
chloride  of  gold  with  a  solution  of  stannous  chloride.  Purple  of 
Cassius  imparts  to  pastes  and  enamels  a  beautiful  purple  color;  it 
is  prepared  as  follows:  Dissolve  30.86  grains  of  tin  in  boiling 
aqua  regia,  evaporate  the  solution  at  a  gentle  heat  until  solid,  then 
dissolve  it  in  distilled  water  and  after  adding  30.86  grains  of  a 
solution  of  stannous  chloride  dilute  with  10  quarts  of  water  and 
stir  into  the  fluid  a  solution  of  chloride  of  gold  prepared  from  0.75 
grain  of  gold  and  not  containing  an  excess  of  acid,  which  is 
effected  by  evaporating  the  solution  of  chloride  of  gold  to  dryness 
and  heating  for  some  time  at  3220  F.  On  adding  1  oz.  12 
drachms  of  ammonia  the  fluid  becomes  turbid  and  the  purple  sepa¬ 
rates  out. 

Plaiinic  chloride  ( chloride  of  platinum,  Tetra-chloride  of  pla- 
tinuni). — This  salt  is  prepared  like  the  chloride  of  gold ;  but  the 
aqua  regia  should  be  made  of  5  parts  of  hydrochloric  acid  to  3  of 
nitric  acid.  The  product  is  evaporated  nearly  to  dryness  in  a 
porcelain  capsule  from  which  it  may  readily  be  detached  after  cool¬ 
ing.  If  it  be  desired  to  have  it  more  acid,  and  therefore  more  easy 
to  dissolve,  it  is  poured  while  still  fluid,  and  not  sensibly  fuming, 
upon  a  porcelain  plate,  from  which  it  is  easily  separated  after  cool¬ 
ing.  Platinic  chloride  is  soluble  in  water  and  alcohol,  caustic  soda 
and  sodium  carbonate  and  phosphate ;  in  the  latter  case  it  forms 
double  salts  like  chloride  of  gold. 

Ammonio-chloride  of  platinum  is  precipitated  from  a  solution  of 
platinic  chloride  by  mixing  it  with  sal-ammoniac  or  another  atn- 
moniacal  salt.  It  is  a  lemon-yellow  powder  soluble  with  difficulty 
in  water.  By  heating  the  powder  spongy  platinutn  is  obtained. 


56 


TIIE  METAL  WORKER’S  IIANDY-BOOK. 


8.  Acids. 

Sulphuric  acid  ( oil  of  vitriol ). — Ordinary  sulphuric  acid  is  a 
colorless,  odorless,  dense  fluid,  which  is  produced  in  large  quantities 
by  oxidizing  in  lead  chambers  moist  sulphurous  acid  by  the  vapors 
of  nitric  acid.  Its  name  of  oil  of  vitriol  comes  from  its  oily 
consistency  and  from  the  green  vitriol  (sulphate  of  iron), 
from  which  it  was  formerly  obtained  by  distillation  in  closed 
vessels. 

Concentrated  sulphuric  acid,  which  may  still  contain  18.46  per 
cent,  of  water,  attacks  and  blackens  organic  substances,  becoming 
itself  more  or  less  dark  thereby.  The  particles  of  dust  flying  in 
the  air  and  falling  into  it  are  sufficient  to  produce  this  phenomenon. 
Sulphuric  acid  is  very  hygroscopic,  i.  e.,  very  much  inclined  to 
absorb  water.  On  mixing  with  water  it  becomes  heated  to  a  con¬ 
siderable  extent.  Now,  as  it  is  frequently  used  in  a  dilute  state,  it 
is  necessary  to  remark  that  water  should  never  be  poured  into  the 
acid ;  pour  the  acid  in  a  thin  jet  and  in  small  quantities  into  the 
water,  stirring  diligently  with  a  glass  rod.  To  avoid  too  much 
heating  and  the  explosion  of  the  mixing  vessel  place  the  latter  in 
another  vessel  filled  with  water.  The  acid  is  preserved  in  glass 
bottles  closed  with  glass  stoppers.  The  value  of  commercial  sul¬ 
phuric  acid  being  dependent  on  its  content  of  anhydrous  acid,  it 
is  tested  with  an  aerometer.  Beaume’s  aerometer  sinks  in  pure 
concentrated  sulphuric  acid,  specific  gravity  1.842  to  66°.  The 
table  on  p.  57  gives  information  in  regard  to  the  content  in  other 
cases ;  it  may  be  remarked  that  the  sulphuric  acid  to  be  tested 
should  be  at  590  F. 

Anhydrous  sulphuric  acid  is  not  found  in  commerce.  Fuming 
sulphuric  acid,  also  called  Nordhausen  sulphuric  acid,  is  obtained  by 
burning  sulphate  of  iron,  and  is  a  mixture  of  anhydrous  and  or¬ 
dinary  sulphuric  acid.  It  is  a  brownish  fluid  of  a  pungent  odor 
(sulphurous  acid)  which  fumes  in  the  air,  and  on  heating  yields 
vapors  of  anhydrous  sulphuric  acid.  Fuming  sulphuric  acid  is 
chiefly  used  for  dissolving  indigo. 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


57 


Percentage  of  Anhydrous  Sulphuric  Acid  at  Different 

Degrees  Be. 


Degrees  B6. 

Anhydrous 

acid. 

Hydrated  sul¬ 
phuric  acid. 

Degrees  Be. 

Anhydrous 

acid. 

Hydrated  sul¬ 

phuric  acid. 

Degrees  Be. 

Anhydrous 

acid. 

Hydrated  sul¬ 

phuric  acid. 

o 

0.7 

0.9 

23 

22.1 

25.8 

46 

46.4 

56.9 

I 

i-5 

1-9 

24 

22.1 

27.1 

47 

47.6 

58-3 

2 

23 

2.8 

25 

23.2 

28.4 

48 

487 

59-6 

3 

3  1 

3-8 

26 

24.2 

29.6 

49 

49.8 

61.0 

4 

3-9 

4.8 

27 

253 

31.0 

50 

51.0 

62.5 

5 

4-7 

5-8 

28 

26.3 

32.2 

5i 

52.2 

64.0 

6 

5-6 

6.8 

29 

27-3 

33-4 

52 

53-5 

65.5 

7 

6.4 

78 

30 

28.3 

347 

53 

54-9 

67.0 

8 

7.2 

8.8 

31 

29.4 

36.0 

54 

56.0 

68.6 

9 

8.0 

98 

32  . 

30-5 

37-4 

55 

57-i 

70.0 

IO 

8.8 

10  8 

33 

31-7 

38.8 

56 

58.4 

71.6 

1 1 

9-7 

1 1  9 

34 

32.8 

40.2 

57 

597 

73-2 

12 

10.6 

13.0 

35 

33-9 

41.6 

58 

61.0 

747 

13 

11  5 

14.1 

36 

35-i 

43-0 

59 

62.4 

76.4 

14  - 

12.4 

15.2 

37 

36.2 

44-4 

60 

63.8 

78.1 

is 

13.2 

16.2 

38 

37-2 

45-5 

6l 

65.2 

79  9 

l6 

14  1 

17  3 

39 

38-3 

46.9 

62 

66.7 

81.7 

17 

15-1 

18.5 

40 

39-5 

48.3 

63 

68.7 

84.1 

18 

16.0 

19.6 

4i 

40.7 

49.8 

64 

70.6 

86.5 

19 

17.0 

20.8 

42 

41.8 

51.2 

65 

73-2 

89.7 

20 

18.0 

22.2 

43 

42.9 

52.8 

66 

81.6 

100.0 

21 

19.0 

233 

44 

44.1 

54.0 

22 

20.0 

24-5 

45 

45-2 

55-4 

Nitric  acid  ( aqua  fords'). — It  is  found  in  commerce  of  various 
colors  and  degrees  of  strength  but  rarely  chemically  pure.  It  is  a 
liquid  of  a  nauseous  smell ;  taste,  strongly  acid.  It  destroys  the 
skin  and  the  majority  of  organic  matters,  dissolves  most  of  the 
metals,  always  with  a  production  of  orange  vapors.  It  is  obtained 
by  decomposing  nitrate  of  soda  with  sulphuric  acid  and  condensing 
the  vapors  formed.  Nitric  acid  may  also  be  diluted  with  water,  the 
same  precautions  as  given  for  sulphuric  acid  being  used.  The 
content  of  anhydrous  and  hydrated  nitric  acid  in  the  mixtures  is 
found  from  the  following  table  : 


58 


THE  METAL  WORKER’S  HANDY-BOOK. 


Percentage  of  Anhydrous  Nitric  Acid  at  Different 
Degrees  Be. 


Degrees  Be. 

Density. 

1 00  parts  contain 
at  320  F. 

100  parts  contain 
at  590  F. 

Anhydrous 
nitric  acid. 

Hydrated 
nitric  acid. 

Anhydrous 
nitric  acid. 

Hydrated 
nitric  acid. 

6 

1.044 

5-7 

67 

65 

7.6 

7 

1.052 

6.9 

8.0 

7-7 

9.0 

9 

1.067 

8.7 

10.2 

9.8 

11  4 

IO 

1.075 

98 

11  4 

10.9 

12-7 

15 

I. I  l6 

15. 1 

17.6 

16.6 

19.4 

20 

1.161 

20.7 

24.2 

22.5 

26.3 

25 

1. 210 

26.9 

3'-4 

28.9 

33-8 

30 

1.261 

33  5 

39  1 

35-6 

4i-5 

35 

1-321 

41. 1 

48  0 

43  5 

5°-7 

40 

1.3S4 

50.0 

58.4 

52.9 

61.7 

45 

1.454 

61.9 

72.2 

71. 1 

78.4 

46 

1.470 

65.2 

76.1 

72.2 

83.0 

47 

1.485 

68.7 

80.2 

74-7 

87.1 

Hydrochloric  acid. — This  acid  is  gaseous,  and  emits  abundant 
and  dense  fumes  in  contact  with  air.  Water  at  the  temperature  of 
68°  F.  dissolves  460  times  its  own  volume  of  this  acid ;  that  is,  1 
quart  of  water  will  dissolve  460  quarts  of  this  gas  and  the  original 
volume  of  the  water  will  be  increased  about  one-third.  It  is 
this  solution  of  the  acid  that  is  found  in  commerce  and  always 
employed  in  the  arts  ;  it  is  generally  contaminated  with  sulphurous 
and  sulphuric  acids,  and  by  perchloride  of  iron  which  imparts  to  it  a 
yellow  color.  A  concentrated  solution  of  hydrochloric  acid  in 
contact  with  moist  air  emits  dense  fumes  which  are  the  most  ap¬ 
parent  in  the  presence  of  ammoniacal  vapors.  Hydrochloric  acid 
is  mostly  obtained  as  a  by-product  in  the  manufacture  of  soda. 
The  content  of  gaseous  hydrochloric  acid  in  hydrated  hydrochloric 
acid  will  be  seen  from  the  following  table : 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


59 


Percentage  of  Gaseous  Hydrochloric  Acid  at  Different 

Degrees  Be. 


Degrees  BA 

100  parts  contain 
gaseous  acid. 

Degrees  BA 

100  parts  contain 
gaseous  acid. 

Degrees  BA 

IOO  parts  contain 
gaseous  acid. 

at  320  F. 

at  59°  F. 

at  3  2°  F. 

at  590  F. 

at  320  F. 

at  590  F. 

O 

0.0 

0.1 

9 

12.7 

HA 

18 

27.0 

28.4 

I 

1-4 

15 

IO 

14.2 

15.0 

19 

28.7 

30.2 

2 

2.7 

29 

I  I 

1 5-7 

16.5 

20 

3<=4 

32.0 

3 

4.2 

4-5 

12 

17.2 

18.1 

21 

32-3 

33  9 

4 

5-5 

5-8 

13 

18.9 

19.9 

22 

34-i 

35-7 

5 

6.9 

7-3 

14 

20.4 

21-5 

23 

36.1 

37-9 

6 

8.4 

8.9 

is 

21.9 

23.1 

24 

38.0 

39-8 

7 

9  9 

IO.J. 

l6 

23.6 

24.8 

25 

40.2 

424 

8 

11.4 

12.0 

17 

25.2 

26.6 

Aqua  regia  (nitro-muriatic  acid )  is  a  mixture  of  2  parts  hydro¬ 
chloric  acid  and  x  nitric  acid  (seep.  39).  But  as  both  acids  occur 
in  commerce  in  different  degrees  of  strength  it  will  be  readily  seen 
that  the  action  of  aqua  regia  will  not  always  be  equally  vigorous. 
To  always  obtain  aqua  regia  of  an  equal  strength  take 


For  100  parts 
of  hydro¬ 
chloric  acid. 

Nitric  acid  of 

42° 

38° 

34° 

2  90 

240 

1 90 

25° 

108 

126 

IS® 

178 

218 

284 

230 

94 

108 

130 

154 

190 

246 

20° 

82 

96 

1 14 

136 

168 

218 

1 8° 

72 

84 

IOO 

118 

146 

190 

1 6° 

62 

72 

86 

102 

126 

162 

13° 

52 

60 

72 

86 

106 

136 

On  mixing  the  two  acids  they  are  decomposed  in  such  a  manner 
that  two  combinations,  gaseous  at  an  ordinary  temperature,  and 
free  chlorine,  are  formed.  It  is  chiefly  due  to  the  content  of 
chlorine  gas  that  aqua  regia  is  the  strongest  solvent  for  metals. 


60 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


Gold  and  platinum  dissolve  only  in  aqua  regia,  and  various  metallic 
sulphides  (cinnabar,  iron  pyrites)  are  decomposed  by  it. 

Chromic  acid  is  obtained  by  adding  to  one  measure  of  a  solution 
of  bichromate  of  potash,  saturated  at  T300  F.,  one  measure  and  a 
half  of  concentrated  sulphuric  acid  and  allowing  the  solution  to 
cool,  when  chromic  acid  crystallizes  out  in  fine  crimson  needles. 
The  needles  adhere  very  firmly  to  the  sides  of  the  vessel,  so  that 
the  fluid  can  be  readily  poured  off  by  inclining  the  vessel.  When 
this  is  done  the  crystals  of  chromic  acid  are  brought  with  the  aid 
of  a  glass  rod  upon  a  porous  brick  which  is  placed  under  a  glass 
bell.  After  24  hours  the  water  adhering  to  the  crystals  has  been 
absorbed  by  the  brick,  and  the  crystals,  which  are  now  entirely  dry, 
are  preserved  in  a  wide-mouthed  bottle. 

Solution  of  chromic  acid  crystals  is  a  very  good  etching  agent 
for  metals.  In  modern  times  it  is  also  frequently  used  as  an  ex¬ 
citant  in  galvanic  batteries. 

Acetic  acid  is  found  in  commerce  in  various  degrees  of  concen¬ 
tration.  Pure  anhydrous  acetic  acid  is  a  colorless  fluid  of  a  very 
acid  taste  and  a  pungent  odor.  At  320  F.  it  solidifies  to  a  crystal¬ 
lized  mass  (glacial  acetic  acid),  which  melts  at  590  F.  In  modern 
times  wood  vinegar  or  pyroligneous  acid  is  employed  in  large 
quantities  ;  it  is  colorless  or  more  or  less  yellow.  It  often  possesses 
an  empyreumatic  odor  and  generally  marks  8°  of  the  hydrometer. 
Wine  vinegar  is  more  or  less  colored,  and  may  be  concentrated. 
Its  smell  is  sufficient  to  distinguish  it. 

Tartaric  acid  is  found  in  commerce  as  powder  and  in  crystals. 
Solutions  of  it  should  be  prepared  immediately  before  use,  as  by 
prolonged  standing  they  easily  decompose  with  the  formation  of 
mould. 

Boric  or  boracic  acid  is  much  used  in  nickelling.  United  with 
sodium  it  constitutes  borax.  In  commerce  it  is  found  in  the  shape 
of  scales  with  nacreous  lustre  and  greasy  to  the  touch.  When  in 
vitreous  masses,  more  or  less  translucent,  it  is  anhydrous  and  has 
been  subjected  to  igneous  fusion.  It  is  also  employed  for  increas¬ 
ing  the  whiteness  of  silver  alloys  and  for  decomposing  the  subsalts 
deposited  in  electro-baths  containing  cyanide  of  potash. 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


61 


Oxalic  acid  ( salt  of  sorrel )  forms  crystals  which,  when  heated  on 
a  platinum  sheet,  fuse  and  burn  without  residue.  It  is  very 
poisonous. 

Prussic  acid  ( hydrocyanic  acid )  is  one  of  the  most  poisonous  sub¬ 
stances  known  and  should  be  used  very  seldom,  and  then  with  the 
greatest  care.  Diluted  prussic  acid  is  colorless,  with  a  bitter  taste  ' 
and  the  characteristic  smell  of  bitter  almonds.  It  is  employed  for 
maintaining  the  strength  of  the  pyrophosphate  of  gold  in  immer¬ 
sion  baths  and  for  decomposing  the  alkaline  carbonates  formed  in 
baths  with  cyanide  of  potassium. 

9.  Various  Chemicals  and  Substances  Used  in  the  Metal 

Industry. 

The  following  substances  used  occasionally  by  the  metal  worker 
are  arranged  in  alphabetical  order: 

Ammonia  ( spirits  of  hartshorn). — This  compound,  which  gener¬ 
ally  bears  the  name  of  ammoniacal  gas  when  in  the  gaseous  form, 
and  of  ammonia  when  in  solution,  presents  properties  similar  to 
those  of  potash,  soda  and  other  alkalies  which  are  metallic  oxides. 
On  account  of  this  analogy  it  is  customary  to  consider  it  as  the 
oxide  of  a  hypothetical  metal,  ammonium,  a  compound  radical 
composed  of  nitrogen  and  hydrogen.  Gaseous  ammonia  dissolves 
in  water  eagerly,  one  volume  absorbing,  when  cold,  about  500 
volumes  of  the  gas.  Aqua  ammonia  is  a  colorless  liquid,  possessing 
a  characteristic  and  overpowering  pungent  smell.  Ammonia  restores 
the  blue  color  of  litmus  reddened  by  an  acid  and  saturates  the  af¬ 
finities  of  the  most  powerful  acids,  and  on  this  account  is  often 
employed  for  removing  acid  stains  upon  clothes.  The  aqua  am¬ 
monia  used  in  the  arts  is  obtained  chiefly  from  the  ammoniacal 
liquor  resulting  from  the  destructive  distillation  of  coal  for  the 
manufacture  of  gas. 

Ammonium  phosphate. — This  salt  is  obtained  by  the  exact  satura¬ 
tion  of  phosphoric  acid  with  ammonia.  The  liquid  obtained  is 
then  evaporated  at  a  gentle  heat,  and  a  few  drops  of  ammonia  are 
now  and  then  added  in  order  to  compensate  for  that  removed  by 


62 


TITE  METAL  WORKER’S  HANDY-BOOK. 


the  decomposition  of  small  quantities  of  the  salt.  When  the 
liquid  becomes  syrupy  it  is  set  aside  to  crystallize  in  a  cool  place. 
This  salt  is  used  for  the  composition  of  baths  for  thick  platinum 
deposits. 

Ammonium  sulphide  ( sulphydrate ,  or  hydrosulphate  of  ammonia) 
is  a  liquid  and  of  a  deeper  color,  according  as  it  contains  more 
sulphur.  Its  smell  is  exceedingly  pungent  and  offensive,  and  its 
taste  is  alkaline  and  nauseous.  The  sides  of  the  bottles  in  which 
it  is  kept  are  often  covered  with  a  pellicle  of  sulphur  or  sulphides. 
By  rapid  evaporation  a  residue  of  sulphur  is  left.  It  rapidly  forms 
sulphides  with  the  metals  and  produces  on  silver  the  black  coating 
misnamed  oxidation.  It  is  often  employed  for  bronzing,  for  pro¬ 
ducing  the  so-called  “  patina”  on  the  surface  of  various  metals  or 
alloys.  It  is  prepared  by  saturating  ammonia  with  sulphuretted 
hydrogen  gas. 

Benzine  ( benzole ,  light  oil  from  coal-tar)  is  a  clear  fluid  of  a 
characteristic  odor;  it  is  very  volatile  and  inflammable.  It  is  an 
excellent  solvent  for  all  the  oils,  resins,  gums,  varnishes,  fats,  etc. 

Borax  (. sodium  biborate)  occurs  generally  in  colorless  prismatic 
crystals,  which  swell  up  on  heating,  and  before  the  blow-pipe  form 
a  colorless  glass.  This  glass  dissolves  nearly  all  the  metallic 
oxides,  and  on  account  of  this  borax  is  much  used  for  tests  with 
the  blow-pipe,  and  in  hard-soldering.  Borax  is  employed  for 
restoring  the  shade  of  defective  gildings  and  for  destroying  the  sub¬ 
salts  of  silver  formed  in  electro-silvering  baths  and  which  injuriously 
affect  the  color  of  the  electro-silver  deposits. 

Calcium,  potassium  and  sodium  sulphides. — These  salts  are  ob¬ 
tained  by  boiling  the  alkali  and  flowers  of  sulphur  in  a  certain 
quantity  of  water.  In  commerce  they  are  found  in  fused  brown 
masses,  the  potassium  sulphide  especially  being  known  .as  liver  of 
sulphur.  They  dissolve  in  water  with  a  yellow  or  red  color  and 
have  the  characteristic  odor  of  sulphuretted  hydrogen ;  when  treated 
by  an  acid  they  give  off  sulphuretted  hydrogen,  yielding  at  the 
same  time  a  deposit  of  sulphur. 

Caoutchouc  ( India  rubber,  gum  elastic)  is  extracted  from  the  sap 
flowing  from  incisions  made  in  the  trunk  of  Ficus  elastica  or  cahuca, 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


63 


a  tree  indigenous  to  Java.  When  pure  it  is  white,  but  its  color  is 
generally  brown  or  red,  caused  by  the  smoke  of  the  fire  employed 
in  drying  it. 

The  combination  of  sulphur  with  caoutchouc  furnishes  the  prod¬ 
uct  called  “  vulcanized  rubber ,”  and  by  modification  of  the  treat¬ 
ment  it  may  be  converted  into  the  substance  known  as  “  hard 
rubber,”  which  is  used  for  a  multitude  of  purposes.  Water,  alco¬ 
hol  and  acid  do  not  dissolve  caoutchouc ;  on  the  other  hand, 
ethers,  bisulphide  of  carbon,  essential  oils  and  benzine  dissolve 
and  leave  it  behind  after  the  volatilization  of  the  solvent. 

Carbon  bisulphide  is  a  colorless  clear  fluid  of  very  disagreeable 
odor.  It  is  extremely  volatile,  inflammable  and  burns  with  a  blue 
flame.  Most  resins,  as  well  as  caoutchouc,  gutta-percha,  sulphur, 
and  phosphorus  are  soluble  in  carbon  bisulphide. 

Emery. — As  regards  its  chemical  composition  emery  is  crystal¬ 
lized  alumina  (aluminium  oxide),  the  same  as  the  ruby,  topaz  and 
sapphire.  On  account  of  its  hardness  it  is  used  for  grinding 
metals  and  glass,  and  for  this  purpose  can  be*  had  in  commerce  in 
various  degrees  of  fineness.  Besides,  in  the  shape  of  powder,  it  is 
also  used  secured  to  paper  or  linen  by  glue  (emery-paper,  emery- 
cloth),  as  well  as  mixed  with  shellac,  linseed  oil  and  water-glass 
and  pressed  into  moulds  (emery-wheels,  emery-files). 

Graphite  ( plumbago ,  black  lead). — This  is  nearly  pure  carbon 
and  is  found  in  amorphous  masses  in  several  countries.  It  is  black, 
with  a  metallic  lustre  and  is  difficult  to  ignite.  It  is  employed  for 
imparting  electric  conductivity  to  the  surfaces  of  many  substances 
which  are  not  naturally  conductors,  and  also  for  preventing  adher¬ 
ence  of  two  superposed  metals. 

Gutta-percha  is  the  hardened  milky  juice  of  a  tree  indigenous  to 
the  East  Indies.  It  generally  occurs  in  the  shape  of  large  thick 
blocks.  It  is  of  a  chocolate-brown  color,  very  solid  at  an  ordinary 
temperature  and  insoluble  in  water,  acids  and  alkalies.  Carbon 
bisulphide  and  chloroform  dissolve  it  in  the  cold,  and  oil  of  turpen¬ 
tine  when  heated.  On  heating  gutta-percha  to  from  1120  to  140° 
F.  it  becomes  so  soft  and  plastic  that  it  can  be  brought  into  any 


64 


THE  METAL  WORKER'S  IT  ANDY-BOOK. 


desired  shape.  On  cooling  it  again  becomes  solid,  retaining,  how¬ 
ever,  the  acquired  shape. 

Magnesia  {calcined')  is  a  white  loose  powder,  consisting  of 
magnesium  oxide,  and  is  obtained  by  calcining  carbonate  of  mag¬ 
nesia.  It  is  slightly  soluble  in  water,  and  feebly  alkaline. 

Potassium  bicarbonate. — This  salt  is  white  and  colorless  and  crys¬ 
tallizes  either  in  tabular  form,  like  nitrate  of  silver,  or  in  cubes,  like 
common  salt.  It  is  soluble  in  tepid  water,  without  decomposition  ; 
but  at  the  boiling  point  it  loses  one-fourth  of  its  carbonic  acid  and 
becomes  a  sesquicarbonate.  At  a  red  heat  it  is  transformed  into 
simple  carbonate,  i.  e.,  it  loses  another  fourth  of  carbonic  acid. 

Potassium  cyanide  {white prussiate  of  potash)  is  a  very  poisonous, 
colorless  salt,  with  an  odor  of  prussic  acid.  The  use  of  potassium 
cyanide  in  electro-plating  and  gilding  depends  upon  the  power  of 
the  solution  of  the  salt  to  dissolve  the  cyanides  of  gold  and  silver, 
forming  compounds  which  are  easily  decomposed  by  the  galvanic 
current,  with  deposition  of  metallic  gold  or  silver  upon  any  object 
capable  of  conducting  the  current  which  may  be  attached  to  the 
negative  pole.  Solution  of  potassium  cyanide  is  also  able  to  dis¬ 
solve  metallic  silver  and  sulphide  of  silver,  which  is  taken  advan¬ 
tage  of  in  removing  photographic  stains  from  the  hands  and  in 
cleaning  silver  or  gold  lace. 

Potassium  hydroxide  {caustic  potash)  is  found  in  commerce  in 
sticks  the  thickness  of  a  lead-pencil.  It  is  very  deliquescent  and 
must  be  kept  in  hermetically  closed  bottles. 

Potassium  nitrate  {saltpetre)  readily  yields  a  portion  of  its  oxy¬ 
gen  to  other  bodies,  and  consequently  acts  in  an  oxidizing  manner 
upon  metals,  carbon,  etc.  It  is  also  used  as  a  flux. 

Sodium  bicarbonate. — The  properties,  etc.,  of  this  compound 
correspond  with  those  of  potassium  bicarbonate. 

Sodium  hydroxide  {caustic  soda)  occurs  in  commerce  in  thick 
white  masses.  It  becomes  deliquescent  by  the  absorption  of  car¬ 
bonic  acid  from  the  air,  whereby  it  is  converted  into  carbonate 
of  soda. 

Sodium  phosphate  {tribasic  phosphate  of  soda)  is  prepared  by 
treating  calcined  and  powdered  bones  with  sulphuric  acid  and 


MOST  IMPORTANT  METALLIC  PREPARATIONS. 


65 


letting  the  mixture  rest  for  several  days.  The  acid  phosphate  of 
calcium  is  then  removed  by  washing  the  residue,  and  the  filtered 
liquid  is  saturated  with  sodium  carbonate  until  carbonic  acid  is  no 
longer  disengaged.  The  clear  liquid  is  then  concentrated  until  it 
marks  330  Be.  and  is  allowed  to  crystallize  once  or  several  times. 
Sodium  phosphate  is  used  for  hot  electro-gilding  baths  and  other 
purposes. 

Sodium  pyrophosphate  ( bibasic phosphate  of  soda'). — The  commer¬ 
cial  salt  is  generally  in  the  form  of  a  white  powder,  odorless,  and 
with  a  hot,  saline,  alkaline  and  then  bitter  taste.  It  is  soluble  in 
water,  but  not  so  freely  as  the  preceding  salt. 

Sulphur  occurs  in  commerce  either  in  the  shape  of  sticks  or  of  a 
fine  powder  (flowers  of  sulphur).  On  heating  sulphur  to  446°  F. 
and  suddenly  cooling  it  becomes  soft  and  plastic  and  may  be  used 
for  taking  impressions  of  medals,  etc.  It  is  not  soluble  in  water, 
but  dissolves  in  heated  oils  and  bisulphide  of  carbon.  Metallic 
sulphides  dissolve  in  melted  sulphur,  a  mass  known  as  Spence' s 
metal  being  formed  which  may  be  used  for  casting.  The  color  of 
Spence’s  metal  is  gray,  sprinkled  with  lustrous  dots.  It  has  about 
the  hardness  of  zinc,  a  specific  gravity  of  3.37  to  3.7,  melts  at 
3 200  F.,  expands  on  cooling  and  is  claimed  to  be  capable  of  resist¬ 
ing  well  the  disintegrating  action  of  the  atmosphere  ;  it  is  attacked 
by  but  few  acids,  and  by  them  but  slowly ;  is  insoluble  in  water 
and  may  receive  a  high  polish.  It  makes  clean,  full  castings,  tak¬ 
ing  perfect  impressions  ;  it  is  cheap  and  easily  worked.  It  is  pre¬ 
pared  by  introducing  iron  disulphide  (Fe  S2),  zinc  blende  and 
galena  into  melted  sulphur.  According  to  an  analysis  by  Juptner 
«  it  contains:  iron  disulphide,  57.38  per  cent.  ;  free  sulphur,  32.44; 
zinc  sulphide,  3.93;  various  substances  and  silicic  acid,  5.84; 
cupric  sulphate,  a  trace. 

Tartar  ( potassium  bitartrate). — This  salt  occurs  nearly  pure  in 
wine,  from  which  it  becomes  separated  in  the  shape  of  small  white 
or  red  crystals,  according  to  the  color  of  the  liquor.  It  is  collected 
from  the  sides  of  wine  casks  and  purified  by  bone-black,  in  which 
state  it  is  known  as  cream  of  tartar.  Tartar  is  acid,  slightly  sol- 
5 


G6 


THE  METAL  WORKER’S  IIANDY-BOOK. 


uble  in  water,  and  it  decrepitates  in  the  fire,  where  it  blackens, 
disengaging  a  smell  like  burnt  sugar. 


III. 

DIRECTIONS  FOR  THE  DETERMINATION  OF  THE  CON¬ 
STITUENTS  OF  METALLIC  ALLOYS,  IMPURITIES  OF 
THE  TECHNICALLY  MOST  IMPORTANT  METALS,  ETC. 

Since  most  metals  dissolve  in  nitric  acid,  pour  over  the  sample 
in  a  glass  flask  chemically  pure  nitric  acid  and  assist  solution  by 
careful  heating  over  a  spirit  flame. 

1.  Gold  and  platinum  dissolve  only  in  aqua  regia;  tin  and  an¬ 
timony  are  only  oxidized  by  nitric  acid.  Hence  if  an  undissolved 
residue  of  the  sample  remains  it  indicates  gold,  platinum  or  anti¬ 
mony  (or  carbon  with  cast-iron).  Filter  the  residue,  which  maybe 
termed  A,  from  the  solution  and  treat  it  further  as  given  under  15. 

2.  Dilute  a  sample  of  the  filtrate  (or,  if  filtration  be  not  neces¬ 
sary,  a  sample  of  the  solution)  in  a  test-glass  with  distilled  water. 
If  turbidity  or  a  white  precipitate  appears  it  indicates  bismuth , 
which  has  been  precipitated  as  basic  salt  from  the  solution  by  water. 
The  non-appearance  of  this  reaction,  however,  is  not  conclusive 
proof  of  the  absence  of  bismuth,  since  an  excess  of  nitric  acid 
prevents  the  precipitation  of  basic  bismuth  nitrate.  To  be  cer¬ 
tain,  first  evaporate  the  sample  to  drive  off  the  acid  and  then  dilute 
with  water. 

3.  Another  sample  of  the  solution  is  mixed  with  dilute  sulphuric 
acid.  If  a  white,  granular  precipitate  is  formed,  the  sample  of 
metal  contains  lead,  because  only  sulphates  of  lead  are  insoluble 
in  acids. 

4.  If,  on  mixing  a  portion  of  the  original  solution,  or  in  case  the 
test  for  lead  was  successful,  a  portion  of  the  filtrate  free  from  lead, 
with  pure  hydrochloric  acid,  a  white,  caseous  precipitate  is  formed 
if  the  metallic  sample  contains  silver  or  mercury.  In  case  test 


DETERMINATION  OF  METALLIC  ALLOYS,  ETC. 


67 


No.  3  has  not  been  previously  executed,  a  precipitate  of  chloride 
of  lead  may  also  take  place  if  lead  is  present.  For  the  further 
treatment  of  this  precipitate,  which  may  be  termed  B,  see 
under  14. 

5.  Add  to  a  small  sample  of  the  solution  in  nitric  acid  a  few 
drops  of  caustic  ammonia.  If  the  solution  acquires  a  fine  blue 
color,  the  sample  of  metal  contains  copper. 

6.  To  test  for  mercury  evaporate  a  few  drops  of  the  solution  in 
nitric  acid  to  remove  the  acid  and  dilute  with  water.  If  a  copper 
wire  placed  in  the  aqueous  solution  turns  gray  and  becomes  white 
with  a  metallic  lustre  on  rubbing  with  the  fingers,  the  presence  of 
mercury  is  shown. 

7.  Next  conduct  into  a  somewhat  larger  sample  sulphuretted 
hydrogen,  and  compound  it  with  water  containing  sulphuretted 
hydrogen.  All  metals  mentioned  in  1  to  6  are  precipitated  as 
metallic  sulphides.  Hence  a  precipitate,  which  may  be  termed  C, 
will  generally  be  obtained.  This  precipitate  is  filtered  off,  thor¬ 
oughly  washed  with  water  containing  sulphuretted  hydrogen,  and 
further  tested  for  cadmium  as  given  under  16. 

8.  Neutralize  the  filtrate  from  the  previous  experiment  and  mix 
it  with  ammonium  sulphide.  The  precipitate  formed,  which  may 
be  termed  D,  is  washed  out  with  water  containing  ammonium  sul¬ 
phide  and  tested  according  to  xo.  Magnesium  may  also  be  con¬ 
tained  in  the  filtrate. 

9.  To  determine  magnesium,  evaporate  a  small  quantity  of  the 
filtrate  obtained  in  8  and  add  some  sodium  phosphate  and  ammonia. 
If  the  solution  contains  magnesium  a  crystalline  precipitate  (of 
ammonium  magnesium  phosphate)  is  formed,  which  is  insoluble  in 
ammoniacal  water. 

10.  Pour  dilute  hydrochloric  acid  over  the  precipitate  D  (from  8). 
If  a  black  residue  (consisting  of  sulphides  of  nickel  and  cobalf), 
and  which  may  be  termed  E,  is  formed  it  is  filtered  off  and  further 
tested  according  to  11.  Boil  the  filtrate  until  the  sulphuretted 
hydrogen  is  completely  driven  off,  then  compound  it  with  nitric 
acid,  boil  again  and  evaporate.  Now  compound  it  with  strong 
alkaline  lye  in  excess,  boil  and  filter.  The  precipitate,  which  may 


68 


THE  METAL  WORKER’S  HANDY-BOOK. 


be  termed  F,  is  analyzed  according  to  12.  The  filtrate  may  con¬ 
tain  zinc  or  alumina.  Both  are  determined  according  to  13. 

11.  The  residue  E  (from  10)  is  dissolved  in  hydrochloric  acid,  a 
few  drops  of  nitric  acid  are  added  and  the  solution  is  evaporated 
nearly  to  dryness.  By  adding  some  sodium  nitrate  and  acetic  acid, 
and  after  standing  for  some  time  in  the  heat,  a  yellow  precipitate  is 
formed  if  cobalt  be  present.  After  12  hours  filter  off  and  compound 
the  filtrate  with  caustic  soda.  Nickel  is  present  when  a  greenish 
precipitate  is  formed,  which  does  not  completely  dissolve  in  the 
excess  of  the  precipitating  agent. 

12.  A  portion  of  the  precipitate  F  (from  10)  is  dissolved  in 
hydrochloric  acid  and  a  sample  of  it  tested, 

a.  With  potassium  ferrocyanide  for  iron. 

b.  Melt  another  sample  with  potassium  carbonate  and  potassium 
chlorate,  and  boil  the  melted  mass  with  water.  If  chromium  was 
present  it  has  been  converted  into  chromic  acid  (yellow  solution), 
and  can  be  readily  recognized  by  compounding  the  solution  with 
sugar  of  lead.  If  chromium  is  not  found,  a  portion  of  the  sample 
is  tested  with  the  blow-pipe  for  manganese. 

c.  If  chromium  was  found,  a  portion  of  the  hydrochloric  acid 
solution  is  neutralized  with  potassium  carbonate,  compounded  with 
caustic  soda  in  excess,  and  the  precipitate  tested  for  manganese  and 
the  filtrate  for  zinc,  according  to  13. 

13.  Moisten  the  solution  to  be  tested  for  manganese  upon  a 
platinum-sheet  with  some  soda  and  a  trace  of  saltpetre,  and  let  the 
flame  of  the  blow-pipe  act  upon  it.  If  the  solution  contains 
manganese  a  green  paste  is  obtained,  which  on  cooling  turns  blue- 
green.  The  filtrate  from  10  may  contain  zinc  or  alumina.  Com¬ 
pound  a  portion  of  it  with  sulphuretted  hydrogen  ;  a  white  pre¬ 
cipitate  (sulphate  of  zinc)  indicates  zinc.  Acidulate  another 
portion  with  hydrochloric  acid,  add  ammonia  in  slight  excess  and 
warm.  Alumina,  if  contained  in  the  solution,  is  precipitated  as 
aluminium  hydrate. 

14.  The  white  precipitate  B  (from  4)  may  contain  chloride  of 
silver,  chloride  of  lead  or  subchloride  of  mercury.  Treat  it  with 
much  water  whereby  chloride  of  lead  is  dissolved  ;  the  lead  may 


DETERMINATION  OF  METALLIC  ALLOYS,  ETC. 


69 


then  be  determined,  as  in  3,  with  sulphuric  acid.  Treat  the  residue 
with  ammonia.  If  complete  solution  takes  place  the  residue  con¬ 
sists  of  chloride  of  silver,  and  from  the  solution  the  silver  is  again 
precipitated  as  chloride  of  silver  by  nitric  acid.  A  black  residue, 
insoluble  in  water  and  ammonia,  consists  of  chlorine  and  mercury 
(subchloride  of  mercury). 

15.  The  residue  which  remained  by  dissolving  in  nitric  acid  is 
warmed  in  aqua  regia.  If  a  white,  insoluble  powder  is  separated, 
it  generally  consists  of  chloride  of  silver,  more  rarely  of  chloride 
of  lead.  Though  silver  and  lead  by  themselves  are  soluble  in 
nitric  acid,  by  alloying  with  the  more  noble  metals  they  are 
frequently  protected  from  solution,  and  may  be  contained  in  the 
residue.  They  are  determined  according  to  14.  A  portion  of 
the  solution  is  now  mixed  with  ferrous  sulphate  solution.  A  fine 
brownish  separation  consists  of  metallic  gold.  A  yellow  precipitate 
produced  by  sal-ammoniac  confirms  the  presence  of  platinum. 

If  the  residue  A  consists  of  a  white  powder  it  is  washed  off  with 
water  and  boiled  in  a  flask  with  tartaric  acid.  If  it  is  soluble  it 
consists  of  oxide  of  antimony  ;  if  insoluble  it  contains  tin. 

16.  The  precipitate  C  (from  7)  obtained  with  sulphuretted  hy¬ 
drogen  contains  a  number  of  metallic  sulphides,  a  portion  of 
which  (antimony,  arsenic,  tin,  gold,  platinum)  is  dissolved  by  am¬ 
monium  sulphide.  The  residue  is  boiled  with  dilute  nitric  acid  and 
dissolves,  separating  flaky  sulphur  which  floats  upon  the  solution. 
If  a  portion  remains  undissolved  it  consists  of  oxide  of  mercury. 
From  the  filtered  solution  separate  the  lead  by  means  of  sulphuric 
acid  (see  3)  and  after  settling  filter  and  mix  with  ammonia.  A 
precipitate  indicates  bismuth  ;  a  blue  coloration  copper.  Evaporate 
the  solution  completely,  add  some  acetic  acid  and  water  and  pre¬ 
cipitate  the  copper  with  sulphuretted  hydrogen.  Cadmium,  if 
present,  is  precipitated  as  sulphide  of  cadmium,  and  hence  the  pre¬ 
cipitate  has  to  be  treated  with  boiling  sulphuric  acid.  The  sul¬ 
phide  of  cadmium  is  dissolved  while  sulphide  of  copper  remains 
undissolved.  If  the  alloy  contains  cadmium  yellow  sulphide  of 
cadmium  is  precipitated  from  the  filtrate  by  sulphuretted  hydrogen. 

17.  Some  alloys  contain  arsenic,  it  being  also  found  as  an  im- 


70 


THE  METAL  WORKER’S  HANDY-BOOK. 


purity  in  many  metals.  To  complete  the  analysis  a  test  for  arsenic 
must,  therefore,  also  be  made.  Marsh’s  apparatus  is  used  for  this 
purpose.  It  consists  of  a  flask  a  (Fig.  3),  in  which  hydrogen  gas 
is  developed  from  chemically  pure  zinc  and  dilute  pure  sulphuric 
acid.  The  tube  c  ends  in  a  wide  glass  tube  d,  which  is  filled  with 
calcium  chloride  for  drying  the  gas.  The  gas  escapes  through  the 


F'g’  3- 


P 


smaller  tube  e,  running  to  a  point  at  f  If  now  through  the  funnel 
b  a  few  drops  of  the  metallic  solution  are  brought  into  the  appara¬ 
tus  the  flame  of  hydrogen  will  acquire  a  blue  coloration  if  the 
solution  contains  arsenic,  and  a  white  smoke  of  arsenious  acid  will 
rise  from  it.  The  arsenietted  hydrogen  formed  is  very  poisonous, 
a  few  bubbles  of  it  being  sufficient  to  cause  death.  If  a  piece  of 
glass  or  porcelain  is  depressed  upon  the  flame  it  will  acquire  a  metallic 
mirror  of  arsenic.  This  metallic  mirror,  however,  is  not  an  infal¬ 
lible  test,  since  antimony  produces  the  same  phenomenon.  To 
ascertain  whether  arsenic  or  antimony  has  to  be  sought  for  in  the 
metal  drop  a  little  solution  of  calcium  chloride  upon  the  metallic 
mirror  ;  arsenic  is  immediately  dissolved,  while  antimony  remains 
unchanged. 

To  Distinguish  Genuine  from  Spurious  Gold. — Genuine  gold  dis¬ 
solves  in  chlorine  water  and  the  solution  has  only  a  slightly  yellow¬ 
ish  color.  Hence  chlorine  is  a  safe  agent  to  distinguish  genuine 


DETERMINATION  OF  METALLIC  ALLOYS,  ETC. 


71 


from  spurious  gold.  To  test  the  genuineness  of  gilt  articles  rub 
a  tiny  drop  of  mercury  on  some  corner  of  the  surface  to  be  ex¬ 
amined  ;  it  will  produce  a  white,  silvery  spot  if  the  gold  is  pure 
or  if  there  is  gold  in  the  alloy.  If  this  silvery  spot  does  not  ap¬ 
pear  there  is  no  gold  in  the  surface  exposed.  To  prove  the  cor¬ 
rectness  of  this  result  a  drop  of  a  solution  of  nitrate  of  mercury 
can  be  dropped  on  the  surface,  when  a  white  spot  will  appear  if 
the  gold  is  counterfeit,  while  the  surface  will  remain  unaltered  if 
the  gold  is  genuine.  After  the  operation  heating  the  article 
slightly  will  volatilize  the  mercury  and  the  spots  will  disappear. 
Pure  gold  can  be  distinguished  from  its  alloys  by  a  drop  of  chloride 
of  gold  or  of  nitrate  of  silver.  If  the  gold  is  pure  there  will  be 
no  stain,  but  if  mixed  with  other  metals  the  chloride  of  gold  will 
leave  a  brownish  stain  upon  it  and  the  nitrate  of  silver  a  gray 
stain. 

The  simplest  means  of  distinguishing  genuine  gold  from  a  gold¬ 
like  alloy  consists  in  rubbing  the  article  to  be  tested  against  an 
ordinary  flint  until  a  lustrous  metallic  coloring  remains  upon  the 
latter.  Now  hold  a  strongly-sulphured  burning  match  against  the 
coloring  ;  if  it  disappears  from  the  flint  the  article  is  not  gold. 

To  Test  Gold  Ware. — When  a  sample  of  the  alloy  cannot  be 
had  for  a  chemical  test  the  touchstone  forms  a  means  of  convenient 
examination.  It  consists  of  a  species  of  black  basalt  obtained 
chiefly  from  Silesia.  If  a  piece  of  gold  be  drawn  across  its  sur¬ 
face  a  golden  streak  is  left,  which  is  not  affected  by  moistening 
with  nitric  acid,  whilst  the  streak  left  by  brass  or  any  similar  base 
alloy  would  be  rapidly  dissolved.  Experience  enables  an  operator 
to  determine  by  means  of  the  touchstone  nearly  the  amount  of 
gold  present  in  the  alloy,  comparison  being  made  with  the  streaks 
left  by  alloys  of  known  composition. 

To  Recognize  Light  Gilding  upon  Metallic  Articles. — It  is  fre¬ 
quently  of  importance  to  know  whether  a  metallic  article  has  a 
thin  coating  of  gold,  or  whether  its  gold-like  appearance  is  due  to  a 
lacquer.  To  execute  the  test  clean  a  piece  or  portion  of  the  article 
to  be  tested  with  alcohol  or  ether  and  dissolve  it  in  nitric  acid  free 
from  chlorine.  In  case  the  article  is  gilded  the  layer  of  gold  floats 


72 


TIIE  METAL  WORKER’S  IIANRY-ROOK. 


upon  or  in  the  solution.  In  many  cases  treatment  with  chloroform 
is  required,  the  removal  of  coatings  of  varnish  not  always  being 
accomplished  with  alcohol  or  ether,  and  thus  the  layer  of  varnish 
which  is  not  attacked  by  the  acid  would  lead  to  error.  The  cer¬ 
tainty  of  the  presence  of  gold  is  best  determined  as  follows :  After 
complete  solution  of  the  article  in  nitric  acid  dilute  the  solution 
with  water,  filter  through  a  small  filter,  wash  out,  dry  and  glow. 
The  glowed  residue  is  treated  with  the  assistance  of  heat  with  a 
little  aqua  regia,  poured  off  or  filtered,  if  necessary,  and  the  filtrate 
evaporated  to  dryness  at  a  moderate  heat.  In  the  presence  of  gold 
a  slight,  lustrous  separation  of  gold  will  frequently  be  observed  on 
the  sides  of  the  evaporating  vessel.  Take  up  the  residue  of  evapo¬ 
ration  with  about  0.12  to  0.18  cubic  inches  of  water  and  divide 
the  solution  into  three  portions  which  are  used  for  the  following 
tests:  Addition  of  a  drop  of  concentrated  solution  of  proto¬ 
chloride  of  tin  :  a  content  of  gold  gives  a  dark,  brown  separation. 
Addition  of  a  drop  of  solution  of  ferrous  sulphate  gives  a  brownish 
or  bluish  separation,  and  addition  of  oxygenated  water  a  blue 
separation. 

To  Recognize  Light  Silvering. — On  touching  silvered  articles  with 
a  mixture  of  equal  parts  of  bichromate  of  potassium  and  pure 
nitric  acid  of  1.35  specific  gravity,  a  red  stain  is  produced.  To 
recognize  light  silvering  apply  to  the  article,  previously  cleansed 
with  alcohol  or  ether,  a  drop  of  1.5  per  cent,  solution  of  bisulphide 
of  soda.  After  allowing  the  drop  to  act  for  10  minutes  rinse  it  off 
with  water.  Upon  silvered  articles  a  full,  round,  steel-gray  spot  is 
produced.  Other  white  metals  and  alloys,  with  the  exception  of 
amalgamated  copper,  do  not  show  this  phenomenon,  there  appear¬ 
ing  at  the  utmost  a  ring  at  the  edge  of  the  drop.  Amalgamated 
copper  is  more  quickly  colored  and  acquires  a  more  dead  black 
color  than  silver.  This  test  is  so  sensitive  that  the  spot  appears 
even  if  the  silvering  is  so  thin  that  the  original  color  of  the  article 
shows  through  it. 

Test-water  for  Silver. — This  consists  of  16  parts  chromic  acid  and 
32  of  distilled  water  ;  keep  the  fluid  in  a  well-stoppered  glass  bottle. 
File  into  the  surface  of  the  article  to  be  tested,  rub  the  filed  place 


DETERMINATION  OF  METALLIC  ALLOYS,  ETC. 


73 


upon  the  touchstone  and  apply  the  test-water.  By  detaching  or  rins¬ 
ing  off  the  latter  with  water  it  will  be  shown  whether  the  article  is 
silver  or  silvered.  With  silver  the  touch  becomes  blood-red,  the 
coloration  being  the  more  intense  the  finer  the  silver.  The  touch 
of  silvered  German  silver,  tin,  compositions,  etc.,  is  not  decom¬ 
posed  by  the  test-water,  the  touch  appearing  in  its  original  color, 
or,  at  the  utmost,  with  a  dull  gray  tint. 

To  Distinguish  Tinfoil  from  Lead-foil. — Treat  the  foil  with 
concentrated  sulphuric  acid  ;  tin  is  dissolved,  while  lead  remains 
undissolved. 

To  Lest  Mercury  as  to  its  Purity. — Pour  nitric  acid  over  a  drop 
of  mercury  in  a  dish.  If  pure  the  mercury  moves  for  a  moment 
and  then  remains  quiet  and  motionless.  If  it  contains  foreign 
metals  it  commences  at  once  a  vigorous  circular  motion  which  is 
kept  up  until  the  mercury  is  completely  dissolved. 

Tin  is  generally  tested  as  to  its  purity  by  breaking  it,  whereby  it 
gives  out  a  single,  crackling  sound  (the  cry  of  tin).  To  recognize 
the  nature  of  impurities  dissolve  a  sample  in  aqua  regia  ;  arsenic  and 
antimony  are  detected  by  Marsh’s  apparatus  (see  p.  70).  Mix  another 
portion  of  the  solution  with  potassium  ferrocyanide  :  a  white  pre¬ 
cipitates  indicates  the  purity  of  the  tin  ;  a  blue  precipitate  gener¬ 
ally  the  presence  of  iron,  and  a  red-brown  precipitate  that  of 
copper.  Lead  may  be  detected  by  the  addition  of  sulphuric  acid 
or  Glauber’s  salt. 

Soft  Solders  are  tested  in  the  same  manner.  They  should  con¬ 
tain  only  tin  and  lead.  Some  soft  solders  contain  bismuth  which 
is  detected  by  diluting  the  solution  (see  under  2,  p.  66). 

To  Detect  Lead  in  Tin. — Make  a  solution  of  potassium  bichro¬ 
mate  in  water.  Next  apply  some  acetic  acid  to  the  tin  to  be 
tested  which  will  produce  a  whitish  coating.  Then  apply  some  of 
the  potassium  bichromate  solution  and,  if  the  whitish  coating  turns 
yellow,  the  tin  contains  lead,  and  the  more  the  yellower  the  coating 
becomes. 

To  Test  Brass. — With  a  larger  content  of  lead  brass  becomes 
brittle.  To  detect  the  presence  of  lead  add  to  the  solution  of  the 
brass  in  nitric  acid  a  few  drops  of  sulphuric  acid.  A  conclusion 


74 


TTTE  METAL  WORKER'S  HANDY-ROOK. 


of  the  quantity  of  lead  present  can  be  drawn  from  the  volume  of 
the  precipitate. 

White  metals  should  always  be  tested  with  Marsh’s  apparatus. 
If  the  metallic  mirror  is  only  partially  dissolved  by  chloride  of 
lime,  the  sample  contains  arsenic  and  antimony.  The  other  con¬ 
stituents  are  found  in  the  manner  already  stated. 

Copper  has  to  be  tested  for  arsenic,  bismuth,  lead,  tin,  zinc,  iron, 
antimony  and  sulphur.  By  compounding  the  solution  in  nitric 
acid  with  barium  nitrate  a  white  precipitate  insoluble  in  nitric  acid 
is  formed  in  case  sulphur  is  present. 

Nickel  has  only  to  be  tested  for  copper,  iron  and  cobalt.  The 
manner  of  determining  copper  has  been  given  under  5,  p.  67. 
Iron  can  be  recognized  by  its  reaction  with  potassium  ferrocyanide. 
To  determine  the  presence  of  cobalt  dissolve  the  metal  in  hydro¬ 
chloric  acid,  dilute  the  solution  with  water  and  write  with  a  goose 
quill  upon  a  strip  of  white  paper.  After  drying  heat  the  writing  ; 
if  it  appears  emerald-green  to  blue-green  the  solution  contains 
cobalt.  For  other  methods  see  under  n,  p.  68. 

Acids  are  readily  tested  for  metallic  acids  according  to  the 
directions  previously  given.  If  uncertain  as  to  the  kind  of  acid 
to  be  tested  it  should  be  borne  in  mind  that, 

a,  hydrochloric  acid  gives,  with  nitrate  of  silver,  a  precipitate  of 
chloride  of  silver ; 

b,  sulphuric  acid  gives,  with  a  solution  of  barium  chloride,  a 
precipitate  of  barium  sulphate. 

c,  nitric  acid  does  not  react  upon  both  of  the  above  solutions,  but 
acquires  a  dark  brown  color  by  ferrous  sulphate  ;  however,  if  it  con¬ 
tains  hydrochloric  acid  it  becomes  turbid  by  nitrate  of  silver  and  is 
then  unfit  for  dissolving  silver,  etc.,  and  the  preparation  of  pickle. 

To  Detect  Alloys  in  Gilding. — A  solution  of  chloride  of  copper 
will  show  the  difference  between  gilding  for  which  gold  has  been 
used  and  gilding  with  alloys  of  inferior  metals.  If  the  gilding  be 
imitation  gold,  a  touch  of  the  solution  will  give  a  black  mark, 
copper  separating  out  through  the  zinc  in  the  yellow  metal ;  with 
pure  metal  no  discoloration  will  occur.  The  test  may  also  be 
effected  with  a  solution  of  chloride  of  gold  or  nitrate  of  silver, 


DETERMINATION  OF  METALLIC  ALLOYS,  ETC. 


75 


the  first  of  which  will  give  a  brown  spot,  the  second  a  gray  or 
black  spot ;  neither  has  any  effect  on  gold.  Common  gold  goods 
of  14-karat  gold  will  not  change  their  color  with  nitrate  of  silver. 
Leaf-gold  is  tested  by  being  shaken  up  in  a  closed  bottle  with 
sulphuric  chloride.  Beaten  gold  will  show  no  alteration,  while 
“  metal  ”  leaves  will  grow  gradually  dark. 

To  Test  Eriamel  for  Lead. — For  the  simple  and  rapid  detection 
of  the  presence  of  lead  in  the  enamel  of  culinary  vessels,  apply  a 
drop  of  concentrated  nitric  acid  to  the  enamel  of  the  carefully 
cleansed  vessel  and  evaporate  it  to  dryness  by  gentle  heating. 
Then  moisten  the  place  which  had  been  subjected  to  the  action  of 
the  acid  with  a  drop  of  sodium  iodide,  and  the  presence  of  lead 
will  be  indicated  by  the  formation  of  yellow  iodide  of  lead. 

Ready  Distinctioii  of  Cast-iron ,  Steel  and  Wrought-iron. — Apply 
a  drop  of  nitric  acid  to  the  surface  of  the  article  to  be  tested,  which 
should  be  previously  made  bright  by  filing.  After  allowing  the 
acid  to  act  for  a  few  minutes  wipe  it  off  and  rinse  with  water. 
Upon  wrought-iron  a  dead  white  ash-gray  spot  will  be  clearly  per¬ 
ceptible,  upon  steel  a  brownish-black  one  and  upon  cast-iron  a 
deep  black  one.  By  this  means  it  can  be  readily  determined 
whether  an  article  of  wrought-iron  is  welded  with  steel  and  how 
far  such  welding  extends.  The  entire  test  is  based  upon  the  differ¬ 
ence  of  content  of  carbon  in  the  above  products  of  iron,  cast-iron 
containing  comparatively  the  greatest  percentage  of  carbon,  next 
wrought-iron  and  steel  least ;  by  the  action  of  the  nitric  acid  upon 
the  metallic  surface  the  iron  is  dissolved  and  the  carbon  exposed. 
A  similar  phenomenon  appears  in  etching  meteoric  iron  with  nitric 
acid,  peculiar  figures  being  formed. 

Method  for  Ascertaining  the  Quality  of  Iron  and  Steel. — Good  iron 
is  readily  heated,  is  soft  under  the  hammer  and  throws  out  few 
sparks. 

Coarse  grain  with  bright  crystallized  fracture  or  discolored  spots 
indicates  cold-short,  brittle  iron  which  works  easily  when  heated 
and  welds  well.  Cracks  on  the  edge  of  a  bar  are  indications  of 
hot-short  iron.  A  medium,  even  grain  with  fibres  denotes  good 


iron. 


76 


TITE  METAL  WORKER’S  HANDY  BOOK. 


A  soft,  tough  iron,  if  broken  gradually,  gives  long  silky  fibres 
of  leaden-gray  hue,  which  twist  together  and  cohere  before 
breaking. 

Badly  refined  iron  gives  a  short  blackish  fibre  on  fracture.  A 
very  fine  grain  denotes  hard,  steely  iron,  likely  to  be  cold-short 
and  hard. 

Examination  of  Burnt  Iron. — The  most  recent  method  of  testing 
iron  is  to  microscopically  examine  the  finely  ground  surface.  The 
results  of  such  examinations  by  Wedding  were  as  follows:  Burnt 
iron  is  characterized  by  the  loosening  of  the  coherence  between  the 
separate  crystals  constituting  the  solid  iron.  This  loosening  may 
take  place  at  a  temperature  approaching  the  melting  point  in  con¬ 
sequence  of  the  formation  of  new  crystals,  or  at  lower  tempera¬ 
tures,  by  reason  of  the  crystals  separating  from  each  other  (passing 
the  limit  of  elasticity)  in  such  a  manner  that  by  subsequent  cooling 
off,  the  initial  volume  is  not  regained ;  it  may,  however,  also  take 
place  by  reason  of  a  chemical  change,  which  always  consists  in  an 
absorption  of  oxygen. 

The  external  appearance  is,  in  all  cases,  nearly  the  same ;  the 
texture  is  coarse-grained,  the  separate  grains  showing  a  more  or 
less  lustrous  surface,  while  the  strength  and  ductility  are  diminished. 
For  the  regeneration  of  the  iron  it  becomes  necessary  to  destroy  this 
coarse-grained  texture,  bringing  at  the  same  time  the  split  crystals 
together  either  by  hammering  or  rolling  alone,  or  by  the  simultaneous 
reduction  of  the  oxides.  The  oxide  (as  a  rule  magnetic  oxide  of 
iron,  Fe3  04)  may  also  be  reduced,  without  heating  to  the  melting 
point.  It  is  difficult  to  answer  in  a  scientific  way  the  question 
which  method  should  be  used  for  the  regeneration  of  burnt  iron  ; 
whether  heating  below  the  melting  point  or  heating  with  fusion 
should  be  resorted  to.  In  the  Royal  techno-chemical  experimental 
station,  at  Berlin,  sixteen  tests  were  made,  the  results  of  which 
may  be  briefly  stated  as  follows  :  i.  Burnt  steel  does  not  show  the 
lustrous  network  of  homogeneous  iron  which  characterizes  the  un¬ 
burnt  product.  2.  This  network  disappears  to  a  greater  extent  the 
richer  in  oxygen  the  steel  becomes.  3.  White  and,  as  a  rule,  lustrous 
planes  appear  more  frequently  and  more  perceptibly  the  more  the  steel 


DETERMINATION  OF  METALLIC  ALLOYS,  ETC. 


77 


is  burnt  and  the  more  coarse-grained  its  structure  has  become.  4. 
When  burning  has  progressed  to  the  formation  of  silicic  acid,  drop¬ 
like  separations  show  themselves  in  place  of  crystallized  iron,  even 
with  a  fine-grained  structure.  5.  Highly-burnt  steel  which  has 
become  coarse-grained,  shows  plainly  the  dividing  lines  of  the 
separate  grains  splitting  still  further.  6.  Regenerated  steel  con¬ 
taining  no  silicic  acid  cannot  be  distinguished  from  sound  steel. 
7.  Regenerated  steel  containing  silicic  acid  shows  a  more  intimate 
union  of  the  grains,  but  can  be  plainly  recognized  by  the  dividing 
lines. 

Resistance  of  a  Few  Metals  and  Alloys  to  Calcium  Hydrate.— 
Filings  and  turnings  of  the  metals  to  be  examined,  in  quantities  of 
77  grains,  were  left,  at  a  normal  temperature,  to  the  action  of  milk  of 
lime  with  4  per  cent,  hydrate  for  14  days;  they  were  then  separated 
from  the  lime  solution  by  washing  until  phenolpthaleine  showed  no 
longer  a  red  coloration,  dried  and  weighed.  The  results  were  as 
follows : 

1.  “  Saxonia  ”  pure  soft  lead:  loss  of  weight  0.811  per  cent. 
The  metal  was  considerably  attacked. 

2.  Antimony  regulus  :  the  metal  remained  entirely  unchanged. 

3.  Lead  pipe  (with  25  per  cent,  slag  lead)  :  loss  of  weight,  0.299 
per  cent.  ;  considerably  attacked. 

4.  Lead  plate  (12  per  cent,  slag  lead):  loss  of  weight,  0.658 
per  cent.  ;  considerably  attacked. 

5.  Pure  cast-iron:  increase  in  weight,  0.014  per  cent.;  very 
much  corroded. 

6.  Brass:  loss  of  weight,  0.686  per  cent.;  considerably  at¬ 
tacked. 

7.  Phosphor-bronze:  no  alteration. 

8.  Pure  tin  :  loss  of  weight,  0.122  per  cent.  ;  the  metal  was  but 
little  attacked. 

From  these  results  it  may  safely  be  concluded  that  for  pumps  in¬ 
tended  for  the  conveyance  of  milk  of  lime  phosphor-bronze  or  an 
alloy  of  tin  and  antimony  is  most  suitable. 

How  to  Tell  a  Hand-  from  a  Machine-ait  File. — Take  the  file 
with  the  tang  pointing  towards  you  and  turn  it  down  under  the 


78 


THE  METAL  WORKER’S  HANDY-BOOK. 


eye  in  such  a  way  that  the  light  will  bring  out  prominently  the 
rows  of  teeth.  If  you  find  the  rows  straight  and  regular  you  can 
at  once  make  up  your  mind  that  it  is  a  machine-cut  file.  If,  on 
the  other  hand,  you  detect  irregularities  in  “  rowing,”  even  if  uni¬ 
formity  is  broken  in  no  other  way,  you  can  safely  decide  that  the 
file  is  hand-cut.  A  double-cut  file  tried  in  this  way  very  readily 
proclaims  its  make. 

In  some  cases,  however,  hand-made  files  are  cut  with  wonderful 
cleverness  and  nicety  ;  so  to  be  always  safe — especially  if  your  eye  is 
inexperienced  in  such  matters  or  is  not  naturally  quick  or  keen, 
the  better  plan  is  to  insist  upon  palpable  regularity  or  irregularity 
in  rowing,  according  to  the  make  of  file  wanted.  And  right  here 
it  is  recommended  that  when  you  have  the  leisure  and  the  privi¬ 
lege,  whether  you  want  to  buy  files  or  not,  that  you  compare  the 
hand  and  the  machine-cut  article  a  few  times  under  your  eye ; 
afterwards  you  will  be  quite  as  able  to  make  distinctions  as  a  file 
manufacturer  himself. 

Generally  speaking,  the  hand-cut  file  is  preferred  for  soft  metals. 
Manufacturers  of  brass  goods  and  kindred  specialties  frequently 
complain  that  the  machine-cut  file  ridges  the  surface  of  the  object 
filed,  owing  to  the  perfect  regularity  of  the  rows  of  teeth.  Some 
manufacturers  have  attempted  to  overcome  this  prejudice  by  al¬ 
ternating  the  number  of  rows  of  teeth  to  the  inch.  Thus  they  will 
run  sixteen  rows  with  the  machine  to  the  inch,  the  next  time  four¬ 
teen,  the  third  sixteen,  and  so  on. 

The  best  cutting  file  is  the  one  with  a  true  diamond  tooth.  If  a 
file  of  this  kind  is  held  in  the  proper  way,  so  that  the  point  of  the 
diamond  is  brought  straight  against  the  metal,  the  very  heaviest 
cutting  possible  can  be  done.  But  it  should  be  remembered  in 
this  connection  that  a  good  deal  depends  on  the  way  the  teeth  are 
“rowed”  on  the  file;  the  rows  may  lie  in  directions  making  it 
awkward,  if  not  a  matter  of  impossibility,  for  the  user  to  present 
the  teeth  properly  to  the  metal. 


ALLOYS  AND  AMALGAMS. 


79 


IV. 

ALLOYS  AND  AMALGAMS. 

I.  Alloys. — Alloys  are  compounds  of  two  or  more  metals. 
However,  when  one  of  the  metals  entering  into  combination  is 
mercury,  the  result  is  usually  not  termed  an  alloy,  but  an  amalgam. 
Many  alloys  possess  the  characteristics  of  a  mixture  and  the  mean 
properties  of  the  metals  of  which  they  are  composed,  while  others 
approach  more  closely  chemical  combinations  and,  consequently, 
partially  show  other  properties  than  their  components.  As  a  rule, 
alloys  are  more  readily  destroyed  by  external  influences  than  the 
pure  metals,  though  there  are  exceptions  which  show  the  reverse. 
The  color  of  an  alloy  frequently  varies  very  much  from  that  of  the 
metals  used  in  its  preparation,  though,  as  a  rule,  it  approaches 
nearest  to  that  of  the  metal  present  in  greatest  quantity.  There 
are,  however,  some  variations  in  this  respect ;  an  alloy  consisting, 
for  instance,  of  determined  proportions  of  gold,  silver  and  copper 
shows  a  greenish  color,  which,  as  is  well  known,  does  not  apper¬ 
tain  to  any  of  these  metals.  The  ductility  and  hardness  of  the 
metals  also  undergo  considerable  change  in  alloying.  As  a  rule 
the  ductility  decreases,  while  the  hardness  compared  with  that  of 
the  metals  constituting  the  alloy  increases  to  a  considerable  extent. 
A  few  metals,  for  instance  antimony,  possess  in  a  high  degree  the 
property  of  making  metals  harder. 

The  alloys,  as  a  rule,  fuse  at  a  lower  temperature  than  that  at 
which  the  constituent  most  difficult  to  fuse  becomes  fluid.  Thus 
platinum,  which  is  scarcely  fusible  at  all,  readily  combines  with 
any  of  the  inferior  metals,  zinc,  tin  and  some  others.  Again, 
several  of  the  readily  fusible  alloys  melt  below  the  boiling  point 
of  water,  which  is  less  than  half  the  melting  heat  of  tin,  their  most 
fusible  ingredient. 

The  specific  gravity  of  an  alloy  seems  to  depend  upon  the 
amount  of  cohesion  or  attraction  exerted  by  the  constituent  metals 
for  one  another,  and  to  bear  no  reference  whatever  to  the  high  or 
low  specific  gravity  of  those  constituents  in  their  free  state.  It  is 


80 


THE  METAL  WORKER’S  HANDY-BOOK. 


common  among  authorities,  who  publish  determinations  of  specific 
gravities  of  the  alloys,  to  give  the  calculated,  as  well  as  the  observed, 
specific  gravity.  The  calculated  specific  gravity  is  that  which  the 
alloy  would  have  if  there  were  neither  expansion  nor  condensation 
of  the  metals  during  the  act  of  combination.  The  specific  gravi¬ 
ties  should  be  calculated  from  the  volumes  and  not  from  the 
weights.  Dr.  Ure  gives  the  rule  as  follows:  Multiply  the  sum  of 
the  weights  into  the  products  of  the  two  specific  gravity  numbers 
for  a  numerator,  and  multiply  each  specific  gravity  number  into  the 
weight  of  the  other  body,  and  add  the  products  for  a  denominator. 
The  quotient  obtained  by  dividing  the  said  numerator  by  the  de¬ 
nominator  is  the  truly  computed  mean  specific  gravity  of  the 
alloy.” 

The  following  table  of  the  alloys,  whose  density  is  greater  or  less 
than  the  mean  of  their  constituents,  is  given  by  several  writers: 


Alloys  the  Density  of  which  is  Greater  [ 
than  the  Mean  of  their  Constituents. 

Gold  and  zinc. 

Gold  and  tin. 

Gold  and  bismuth. 

Gold  and  antimony 
Gold  and  cobalt. 

Silver  and  zinc. 

Silver  and  tin. 

Silver  and  bismuth. 

Silver  and  antimony. 

Copper  and  zinc. 

Copper  and  tin. 

Copper  and  palladium. 

Copper  and  bismuth. 

Lead  and  antimony. 

Platinum  and  molybdenum. 
Palladium  and  bismuth. 


[  Alloys  the  Density  of  which  is  Less 
than  the  Mean  of  their  Constituents. 

Gold  and  silver. 

Gold  and  iron. 

Gold  and  lead. 

Gold  and  copper. 

Gold  and  iridium. 

Gold  and  nickel. 

Silver  and  copper. 

Iron  and  bismuth. 

Iron  and  antimony. 

Iron  and  lead. 

Tin  and  lead. 

Tin  and  palladium. 

Tin  and  antimony. 

Nickel  and  arsenic. 

Zinc  and  antimony 


The  tenacity  of  an  alloy  is,  as  a  rule,  less  than  that  of  the  most 
tenacious  of  the  component  metals,  a  very  small  quantity  of  lead, 
for  instance,  sufficing  to  decrease  the  tenacity  of  gold,  which  is 
one  of  the  most  tenacious  of  metals.  In  a  few  cases,  however,  the 
alloy  possesses  a  higher  degree  of  tenacity  than  the  constituent 
metals,  there  being,  for  instance,  an  alloy  of  copper  and  zinc 


ALLOYS  AND  AMALGAMS. 


81 


which  is  more  ductile  than  copper,  though  zinc  belongs  to  those 
metals  which  are  distinguished  by  brittleness  rather  than  by 
ductility. 

Alloys  are  generally  made  by  directly  melting  together  the 
metals  which  are  to  take  part  in  the  mixture.  The  operation  may 
be  carried  on  in  an  earthenware  crucible  when  small  quantities  are 
being  operated  upon  ;  but  for  manufacturing  on  a  large  scale  a 
reverberatory  furnace,  preferably  heated  with  gas,  should  be  em¬ 
ployed  to  effect  the  melting.  The  melting  and  mixing  of  the 
several  metals  is  a  point  which  is  far  from  being  reduced  to  any¬ 
thing  like  a  system  in  many  establishments,  and  practical  men  are 
often  at  a  loss  as  to  the  proper  means  for  securing  a  definite  and 
uniform  alloy.  As  a  general  rule  it  is  necessary  to  melt  the  less 
fusible  metal  first  and  to  add  the  more  fusible  afterwards.  Founders 
generally  are  of  the  opinion  that  if  the  metal  of  the  first  melting  is 
run  out  into  a  bar  and  then  remelted  a  more  complete  incorpora¬ 
tion  is  obtained.  Where  a  great  difference  exists  in  the  specific 
gravities  of  the  component  metals,  it  is  necessary  to  observe  certain 
fixed  rules  in  order  to  obtain  a  perfectly  homogeneous  mixture ; 
each  metal  tends  to  find  its  own  particular  level  in  the  liquid 
compound,  according  to  its  density ;  therefore,  if  the  casting  is 
of  considerable  size  and  requires  a  long  time  to  cool,  a  partial 
separation  will  often  take  place,  the  lightest  rising  to  the  surface. 
Therefore,  the  metals,  while  in  a  state  of  fusion,  must  not  be 
allowed  to  remain  quiescent,  but  an  intimate  mixture  be  effected 
by  vigorous  stirring,  sticks  of  dry  soft  wood  being  in  many  cases 
used  for  this  purpose.  By  stirring  the  fused  mass  with  one  of 
these  sticks,  the  wood  is  more  or  less  carbonized  according  to  the 
temperature  of  the  mass.  In  consequence  of  the  dry  distillation 
of  the  wood  taking  place  thereby,  there  is  evolved  an  abundance 
of  gases  which,  by  ascending  in  the  fused  mass,  contribute  to  its 
intimate  mixture.  The  stirring  should  be  continued  for  some  time 
and  the  alloy  then  cooled  as  rapidly  as  possible.  When  three 
metals  have  to  be  united  together,  they  should  first  be  melted  in 
pairs  and  afterwards  together. 

The  following  may  serve  as  general  rules  for  fusing  the  metals : 

6 


82 


THE  METAL  WORKER’S  HANDY-BOOK. 


i.  The  melting-pot  should  be  red  hot,  and  those  metals  first  placed 
in  it  which  require  the  most  heat  to  fuse  them.  2.  Put  the  metals 
in  the  melting-pot  in  strict  order,  following  exactly  the  different 
fusing  points  from  the  highest  degree  of  temperature  required 
down  to  the  lowest,  in  regular  sequence,  and  being  especially 
careful  to  refrain  from  adding  the  next  metal  until  those  already  in 
the  pot  are  completely  melted.  3.  When  the  metals  fused  together 
in  the  crucible  require  very  different  temperatures  to  melt  them,  a 
layer  of  charcoal  should  be  placed  upon  them,  or  if  there  is 
much  tin  in  the  alloy,  a  layer  of  sand  should  be  used.  4.  The 
fused  mass  should  be  vigorously  stirred  with  a  stick,  and  even 
while  pouring  it  into  another  vessel  the  stirring  should  not  be  re¬ 
laxed.  5.  In  making  new  alloy,  use  a  little  old  alloy  of  the  same 
kind,  if  there  be  any  on  hand.  6.  Make  sure  that  the  melting-pots 
are  absolutely  clean  and  free  from  traces  of  former  operations. 


The  fusing  points  of  the  principal  metals  and  other  elements  em¬ 
ployed  in  alloys  are  as  follows : 


Aluminium . 

12920  F. 

Lead . 

.  626°  F 

Antimony . 

797  “ 

Mercury . 

. —40  “ 

Arsenic . 

773  “ 

Nickel . 

Bismuth . 

5°4  “ 

Phosphorus . 

Cadmium . 

608  “ 

Platinum . 

. 4712  “ 

Copper . 

1922  “ 

Silver . 

. 1832  “ 

Gold . 

2282  “ 

Sulphur . 

.  239  “ 

Iron,  cast . 

to 

2192  “ 

Tellurium . 

“  wrought. .  .  . 

. 2732 

to 

2912  “ 

Tin . 

.  455  “ 

Steel . 

..  ..2372 

to 

2552  “ 

Zinc . 

.  773  “ 

Alloys  of  Bismuth  and  Cadmium. — These  alloys  have  the  pe¬ 
culiarity  that  their  melting  points  are  far  below  those  of  their  con¬ 
stituent  metals,  some  of  them  even  melting  in  hot  water.  They 
can  be  used  for  casting  in  moulds  which  will  not  stand  great  heat, 
for  instance  moulds  of  paper,  wood,  plaster  of  paris,  etc.  The 
composition  of  the  most  important  alloys  belonging  to  this  group 
is  given  in  the  following  table  : 


ALLOYS  AND  AMALGAMS. 


83 


Melts 

at 

°  F. 

Lead. 

Parts. 

Tin. 

Parts. 

Anti¬ 

mony. 

Parts. 

Cad¬ 

mium. 

Parts. 

Bis¬ 

muth. 

Parts. 

Lipowitz’s  alloy . 

.58 

8 

4 

3 

15 

Readily  fusible  alloy . 

170 

II 

3 

2 

l6 

tt  it  it 

I67 

8 

3 

IO 

8 

it  if  it 

203 

2 

I 

3 

a  a  a 

150 

2 

I 

I 

4 

Wood’s  alloys . 

14CU0  1 61 .6 

4 

2 

1  to  2 

5  to  » 

Soft  solder . 

179.6 

6 

I 

7 

“  “  . 

300.2 

2 

4 

2 

Cliche  metal . 

.... 

50 

36 

22.5 

it  a 

32-5 

48 

10.5 

9 

Metallic  cement . 

8 

3 

I 

Newton’s  metal . 

202 

5 

3 

8 

Rose’s  metal . . 

200.75 

I 

I 

2 

a  a 

174.2 

8 

3 

8 

Readily  fluid  metal  suitable  f 

13 

3 

6 

for  impressions  of  plaster  j 

3 

2 

5 

of  paris  moulds,  wood  1 

I 

I 

2 

engravings,  medals,  etc.  [ 

5 

3 

8 

Glass  cement . 

212 

3 

2 

2.5 

Bismuth  alloys . .  .  ,  . 

212 

5 

3 

8 

it  it 

235  9 

8 

4 

8 

it  it 

253-9 

8 

8 

8 

a  it 

266 

IO 

8 

8 

a  a 

270.3 

12 

8 

8 

a  a 

287.9 

l6 

H 

8 

tt  a 

293-7 

l6 

12 

8 

a  a 

308.8 

22 

24 

8 

a  a 

320.3 

32 

36 

8 

a  a 

330-7 

32 

28 

8 

a  tt 

341.6 

30 

24 

8 

Alloys  of  Copper  and  Tin. — Bronze.  The  alloys  produced  by  the 
union  of  copper  and  tin  are  termed  “  bronze"  in  the  actual  sense 
of  the  word  if  the  copper  is  present  in  predominating  quantity, 
while  those  in  which  the  content  of  tin  predominates  are  called 
“  white  metal."  Bronze  has  been  known  and  employed  from  very 
remote  ages.  It  was  used  exclusively  by  the  ancients  for  making 
swords  and  other  sharp  instruments,  for  coinage,  statues  and  many 
other  useful  and  ornamental  purposes.  Great  variations  are  made 
in  the  proportions  of  the  two  chief  ingredients,  according  to  the 
nature  of  the  application  for  which  the  alloy  is  intended.  The  ad¬ 
dition  of  a  little  zinc  to  the  alloy  is  an  advantage,  but  too  much  of  it 


84 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


diminishes  its  tenacity;  lead  is  objectionable,  owing  to  its  tendency 
to  sink  after  casting,  thus  destroying  the  homogeneity  of  the  alloy. 
The  metals  should  be  melted  rapidly  to  prevent  loss  of  metal  by 
oxidation,  and  the  melted  mass  should  be  covered  with  a  layer  of 
charcoal  and  kept  constantly  stirred.  The  operation  is  generally 
carried  on  in  refractory  crucibles,  heated  in  a  reverberatory  furnace 
of  suitable  form.  The  cooling  in  the  moulds  must  be  as  rapid  as 
possible,  in  order  to  prevent  the  liquation  of  the  metals. 

Ordnance  or  Gun-metal. — Gun-metal  contains  on  an  average  90 
to  91  per  cent,  of  copper  and  9  to  10  per  cent,  of  tin  ;  sometimes 
it  contains  some  lead  and  zinc.  The  principal  requisite  of  an  al¬ 
loy  answering  all  the  demands  of  a  good  ordnance  bronze  is  the 
production  oTentirely  homogeneous  castings,  which  it  is  endeavored 
to  attain  by  solidifying  the  alloy  under  conditions  allowing  of  its  uni¬ 
form  cooling  off.  The  moulds  are  always  placed  in  a  vertical  position, 
and  the  evil  of  the  upper  portions  of  the  casting  showing  fre¬ 
quently  a  different  composition  from  the  lower,  is  counteracted  by 
using  an  excess  of  bronze,  so  that  the  finished  casting  has  a  long 
piece  on  top,  the  so-called  “dead-head  or  “  sullage-piece,”  which 
is  later  on  sawed  off  and  remelted  with  a  new  charge.  This  dead¬ 
head  contains  the  greater  portion  of  the  liquated  metal,  and  also 
the  so-called  “  waste”  consisting  of  oxidized  metal. 

The  following  table  shows  the  composition  of  ordnance  bronze 
of  various  times  and  different  countries : 


Copper 

Parts. 

Tin. 

Parts. 

Lead. 

Parts. 

Zinc. 

Parts. 

Iron. 

Parts. 

Brass. 

Parts. 

United  States . . 

France  (modern) . 

Prussia . 

England . 

France  (1780) . 

Savoy  (Turin,  1771) . 

Russia  (1819), . 

Lucerne  (Switzerland)  . 

Cochin-China . | 

90 

90.09 

90.90 

89-3° 

IOO 

IOO 

88  6l 
88.929 
77-iS' 
93->9 
71.16 
89.5S 
95-20 

10 

9.9 

9-1 

10.7 

12.0 

10.7 

10-375 

3-42 

5-4-3 

10.15 

4.71 

0.062 

13.22 

0.419 

5-02 

27  16 

O.69 
0.1 10 
1. 16 
1.38 
1.40 

6l  .O 

6.0 

Turkey  (1464) . j 

.  . .  j  .. 7. 

ALLOYS  AND  AMALGAMS. 


85 


Steel  Bronze  or  Uchatius  Bronze. — The  ordnance  bronze  known 
under  this  name  is  prepared  in  the  Austrian  arsenals,  the  method 
of  melting  and  subsequent  treatment  in  casting  being  kept  secret. 
It  is  only  known  that  the  bronze  contains  8  per  cent,  of  tin  and 
that  the  casting,  is  effected  in  cold  moulds.  In  casting  a  copper 
rod  about  2  inches  in  diameter  is  inserted  as  a  core  in  the  centre 
of  the  iron  mould.  It  serves  as  a  conductor  of  heat  and  later  on  is 
bored  out.  The  alloy  is  crystalline  and  of  a  gold-yellow  color.  To 
increase  the  solidity  of  the  piece  steel  bolts  with  a  diameter  of  from 
0.39  to  2.36  inches  are  forced  in  by  means  of  a  hydraulic  press. 

Bell-metal  contains  on  an  average  78  per  cent,  of  copper  and  22 
per  cent,  of  tin.  The  color  of  good  bell-metal  is  a  peculiarly  gray 
white,  differing  materially  from  that  of  ordnance  bronze  and 
statuary  bronze.  Bell-metal  is  hard,  brittle  and  sonorous  and  ex¬ 
hibits  a  fine-grained  fracture.  Cooled  suddenly  from  a  red  heat  it 
becomes  soft,  but  regains  its  hardness  after  being  reheated  and 
cooled  very  slowly.  The  larger  the  proportion  of  copper  in  the 
alloy  the  deeper  and  graver  is  the  tone  of  the  bells  formed  from  it. 
The  addition  of  tin,  iron  or  zinc  causes  them  to  give  out  a  sharper 
tone.  The  opinion  was  formerly  held  that  an  addition  of  silver 
adds  to  the  beauty  of  the  tone,  though  at  present  it  is  thoroughly 
understood  that  such  is  not  the  case.  The  melting  and  casting  of 
bell-metal  is  not  so  difficult  as  that  of  ordnance  bronze,  though 
great  analogy  exists  between  them.  The  copper  is  first  melted 
down,  and  after  heating  the  fused  mass  as  much  as  possible  the  tin 
is  introduced  and  an  intimate  mixture  promoted  by  vigorous 
stirring.  Many  bell-founders  do  not  add  all  the  tin  at  once,  but 
at  first  about  two-thirds  of  it,  and  when  this  has  formed  a  union 
•with  the  copper  the  other  third. 

Chinese  Tam-tams  or  Gongs  are  distinguished  by  a  strong  far- 
reaching  sound.  The  alloy  of  which  they  are  made  is  nearly  of 
the  same  composition  as  the  ordinary  bell-metal,  the  difference  in 
sound  being  due  to  mechanical  treatment.  As  soon  as  the  plates 
intended  for  the  manufacture  of  tam-tams  are  well  solidified,  they 
are  withdrawn  from  the  mould  and  introduced  into  a  furnace  where 
they  are  raised  to  a  cherry-red  heat.  They  are  then  inserted 


8(1 


TTTE  METAL  WORK  EL’S  HANDY-BOOK. 


between  iron  disks,  plunged  into  water  and  allowed  to  cool,  after 
which  they  are  withdrawn,  and  are  so  tenacious  that  they  may  be 
worked  under  the  hammer. 

The  following  table  shows  the  composition  of  some  bell-metals: 


Parts. 

Copper. 

£ 

Zinc. 

Lead. 

Silver. 

Iron. 

Anti- 
[  mony. 

Standard,  very  sonorous . 

39 

1 1 

Plunders’  standard,  paler  and 

inferior  to  above . 

77 

21 

.... 

2 

Very  deep  toned  and  sonorous... 

40 

IO 

For  church  and  other  large  bells. 

3° 

IO 

Alarm  bell  at  Rouen . 

76.1 

22.3 

1.6 

1.6 

“  “  “  Ziegenhain . 

7C4S 

33-59 

.... 

4.04 

0.12 

“  “  “  Darmstadt . 

73  94 

21.67 

1. 19 

0.17 

“  “  “  Reichenhall 

(13th  Century). . 

80 

20 

Tam-tam . -1 

7S.51 

10.27 

0.52 

0.18 

IO 

4 

i-5 

0.5 

f 

IO 

2-5 

o-5 

i-33 

Bells  of  Japanese  origin . J. 

10 

3 

I 

2 

05 

[ 

IO 

Bell-metal  for  Small  Bells,  which  is  said  not  to  tarnish  nor 
crack  and  to  be  very  light  in  weight  and  give  an  excellent  sound, 
is  composed  of  copper,  3  lbs.  ;  nickel,  y2  lb.,  melted  and  cooled  ; 
then  add  y2  lb.  zinc  and  oz.  aluminium  ;  melt  and  cool.  Melt 
again  and  add  y  oz.  mercury  and  3  lbs.  melted  copper. 

Japanese  Bell-metal. — This  alloy,  called  “  Karakane  ”  by  the 
Japanese,  is  cast  in  various  qualities.  I.  Copper,  10  parts;  tin,  4  ; 
iron,  y2  ;  zinc,  1  y.  II.  Copper,  10  parts;  tin,  2)4  lead,  r  ; 
zinc,  y2.  III.  Copper,  10  parts;  tin,  3  ;  lead,  2;  iron,  y2  ;  zinc,  1. 
IV.  Copper,  10  parts;  tin,  2;  lead,  2. 

Small  Clock-bells ,  Table-bells,  Sleigh-bells,  etc. — For  these  an 
alloy  giving  a  clear  and  pure  tone  has  to  be  used.  The  following 
table  will  suffice  to  show  the  composition  of  such  alloys: 


ALLOYS  AND  AMALGAMS. 


87 


Parts. 

Copper. 

Tin. 

Zinc. 

Lead. 

Silver. 

Anti¬ 

mony.  | 

Bis¬ 

muth. 

House-bells . 

“  “  smaller . 

Clock-bells,  German . 

“  “  Swiss . 

“  “  Paris . 

Sleigh-bells . 

White  table-bells . 

tt  ((  (( 

80 

75 

73 

74-5 

72.0 

84.5 

17 

20 

25 

24-3 

25 

26.56 

15.42 

800 

7 

2.7 

0-5 

1.44 

0.1 

1 

5 

Silver  Bell-metal. — This  alloy,  suitable  for  small  bells,  is  dis¬ 
tinguished  by  a  beautiful  silver-clear  tone  and  a  nearly  white  color. 
It  is  composed  of 

Parts. 


I.  II.  III. 

Copper .  40  41.5  41.6 

Tin.... .  60  58.5  58.4 


Machine  Bronze. — In  this  collective  term  are  included  a  great 
number  of  alloys  with  very  variable  properties,  and  which  have 
actually  nothing  in  common  except  that  they  are  used  for  certain 
parts  of  machines.  Many  of  these  mixtures  of  metals  must  be  as 
hard  as  possible  in  order  to  resist  wear  ;  others  must  possess  great 
strength,  so  as  not  to  yield  under  shocks  or  pressure  ;  while  still 
others  must  have  the  property  of  showing  even  under  a  heavy  load 
but  little  frictional  resistance  when  in  contact  with  other  metals. 
There  are  two  kinds  of  bearing-metal,  viz.  :  red  brass  and  white 
metal ,  the  former  being  bronze-like  alloys  with  from  82  to  89  per 
cent,  of  copper  and  n  to  18  per  cent,  of  tin.  By  the  addition  of 
zinc,  lead  and  antimony,  the  hardness  or  ductility  of  the  alloy  is 
changed  according  to  the  purpose  for  which  it  is  to  be  used.  An 
addition  of  lead  facilitates  the  working  of  the  alloy  but  also  favors 
liquation  ;  antimony  increases  the  hardness  of  the  alloy. 


88 


THE  METAL  WORKER’S  HANDY-BOOK. 


White  bearing  metal  is  distinguished  from  red  brass  by  being 
more  readily  fusible,  so  that  it  can  frequently  be  cast  around 
the  respective  pivot.  It  consists  of  tin,  74  to  91  per  cent.,  antimony, 
6  to  15,  and  copper,  2  to  xi.  The  copper  increases  the  hardness 
and  strength  of  the  alloy.  In  English  bearing-metal  a  portion  of 
the  tin  is  replaced  by  zinc  or  lead.  Small  quantities  of  other 
metals  besides  tin,  lead,  zinc,  antimony  and  copper,  which  occur 
in  the  alloys,  must  be  considered  as  impurities  of  the  metals  used. 


Metals  for  Bearings,  Etc. 


I.  Red  Brass  Bearings,  etc. 

Parts. 

Copper. 

Zinc. 

Tin. 

Lead. 

For  locomotive  axles . 

86 

14 

“  railroad  car  axles . 

tt  tt  tt  tt 

S2 

82 

84 

8 

18 

16 

IO 

tt  tt  tt  tt 

75 

2 

20 

“  various  axles . 

73  7 

2.1 

14.2 

“  “  “  (medium  hard) . 

6955 

5-SS 

21.77 

“  “  “  (hard) . 

“  “  “  (very  hard) . . 

“  cog-wheels . 

“  punches  . 

82 

S8.8 

9i-3 

833 

2 

1 1.2 

8.7 

16.7 

16 

“  steam-whistles . 

So 

2 

17 

it  it  it 

81 

2 

16 

“  cocks . 

88 

2 

IO 

“  boxes  for  wagon-wheels . 

87.7 

2.6 

9-7 

“  stuffing-boxes . 

S6.2 

3-6 

10.2 

“  mechanical  instruments . 

81.2 

5-i 

12.8 

“  files . 

64.4 

IO 

17.6 

8.6 

tt  it 

61.5 

7-7 

3°.s 

“  weights . 

90 

2 

8 

“  castings  to  be  gilded . 

79.1 

7.8 

•3-1 

a  a  tt  tt 

77.2 

7 

158 

“  shovels  (malleable) . 

tt  tt  tt 

50 

16.4 

33-6 

3 

2 

I 

“  buttons  (white)  . 

57  9 

36.8 

5-3 

“  sheet  for  pressed  articles . 

“  small  castings . 

63.88 

94.12 

90 

3°-55 

5-55 

5.88 

tt  it  it 

IO 

“  piston  rings . 

84 

8-3 

2.9 

4-3 

“  pump  barrels . 

88 

2 

IO 

“  eccentric  straps . 

90 

2 

8 

ALLOYS  AND  AMALGAMS. 


89 


Metals  for  Bearings,  Etc. — Continued. 


Parts. 


II.  White  Metal  Bearings. 


German  for  light  loads. .  . . 

tt  it  it  it 

it  it  it  it 

it  ti  it  it 

tt  ft  tt  it 

“  “  heavy  “  .... 

((  it  it  it 

English  for  heavy  loads. .  . . 

“  “  medium  “  .... 

tt  tt  tt  it 

For  mills. .  . 

it  it 

tt  tt 

For  heavy  axles  . 

it  it  tt 

For  rapidly  revolving  axles 
Bearings  of  great  hardness.. 

it  it  ti 

“  (cheap) . 

tt  it 

For  railroads  : — 

Prussia . 


Prussian  and  Hanoverian  rail¬ 
roads  approved  under  the 

heaviest  pressure. . . . 

Bavaria,  durable  cold  running.  . 

Austria  government  railroad . 

Distributing  slide  valves . 

Railroad  cars  and  larger  ma¬ 
chines  . 

Railroad  cars,  harder  and  f 
stronger . ( 


Tin. 

Anti¬ 

mony. 

Zinc. 

Iron. 

Lead. 

Copper 

85 

10 

5 

82 

1 1 

.... 

7 

80 

12 

8 

76 

17 

7 

3 

1 

5 

3 

I 

90 

8 

2 

86.81 

7.62 

5-57 

17-47 

76.14 

5.62 

76.7 

15-5 

7.8 

72 

26 

2 

15 

40 

42 

3 

I 

5 

5 

I 

IO 

2 

72.7 

18.2 

. 

9.1 

38 

6 

47 

4 

I 

17 

77 

. 

6 

5 

70 

2-5 

12 

82 

2 

4 

2 

2 

88 

8 

i-5 

*•5 

90 

7 

91 

6 

. 

3 

85 

IO 

5 

80 

12 

8 

86.81 

7.62 

5-57 

90 

8 

2 

90 

7 

3 

83.2 

II. 2 

5.6 

l6 

84 

20 

20 

60 

12 

8 

80 

Locomotive  Brass  Castings. — The  following  compositions  are 
highly  recommended  : 

Brasses  for  Side  Rods.-- Copper,  6  lbs.  ;  tin,  i  lb.  To  ioo  lbs. 
of  this  mixture  add  y2  lb.  each  of  zinc  and  lead. 


90 


TTTE  METAL  WORKER’S  HANDY-BOOK. 


Brasses  for  Driving-Boxes. — The  same  as  for  side  rod  brasses. 

Some  master  mechanics  prefer  harder  brasses  and  call  for  5  lbs. 
of  copper  and  1  lb.  of  tin,  y2  lb.  of  zinc  and  y2  lb.  of  lead. 

Bells. — Copper,  4  lbs.  ;  tin  1  lb.  To  every  100  lbs.  of  this  mix¬ 
ture  add  zinc,  y2  lb.,  and  lead  y2  lb. 

Castings  subjected  to  Steam  Pressure. — Copper,  20  lbs.  ;  tin,  1  y2 
lbs. ;  lead  and  zinc,  of  each  1  lb. 

Pumps  a?id  Bump  Chambers. — Copper,  8  lbs.  ;  tin,  1  lb.  To 
every  100  lbs.  of  this  mixture  add  1  y2  lbs.  each  of  lead  and  zinc. 

Piston  Packing  Rings. — Copper,  16  lbs.  ;  tin,  2]j  lbs.  To  every 
100  lbs.  of  this  mixture  add  1  lb.  each  of  zinc  and  lead. 

Approved  Compositions  for  Bearings  of  Rapidly  RunningMachines. 
— I.  Tin,  17  parts;  antimony,  77;  copper,  6.  II.  Copper,  86 
parts;  zinc,  14.  III.  Copper,  82;  zinc,  18.  IV.  Copper,  84; 
zinc,  16.  V.  Copper,  100;  zinc,  10;  tin,  3.  VI.  Tin,  17.47; 
zinc,  76.14;  copper,  5.69. 

Bearing  Metals  for  Locomotives. — I.  Copper,  86  parts;  tin,  14. 
II.  Dutch.  Copper,  85.25  parts;  tin,  127.5;  zinc,  2.  III.  Ap¬ 
proved  Belgian.  Copper,  80  parts  ;  tin,  16  :  lead,  2  ;  antimony,  2. 
IV.  French  Northern  Railroad.  Copper,  82  parts  ;  tin,  xo  ;  zinc, 
8.  V.  Copper,  87.5  parts;  tin,  7.88;  zinc,  5.07.  VI.  Copper, 
79.5  parts;  tin,  7.5  ;  zinc,  5;  lead,  8. 

Babbitt' s  Anti-Attrition  Metal  is  made  by  melting  separately  4 
parts  of  copper,  12  of  Banca  tin,  8  of  regulus  of  antimony  and 
adding  12  parts  of  tin  after  fusion.  The  antimony  is  added  to  the 
first  portion  of  tin  and  the  copper  is  introduced  after  taking  the 
melting-pot  away  from  the  fire  and  before  pouring  it  into  the 
mould.  The  charge  is  kept  from  oxidation  by  a  surface  coating 
of  powdered  charcoal.  The  “lining  metal”  consists  of  this 
“  hardening  ”  fused  with  twice  its  weight  of  tin,  thus  making  3.7 
parts  copper,  7.4  parts  antimony  and  88.9  tin.  The  bearing  to  be 
lined  is  cast  with  a  shallow  recess  to  receive  the  Babbitt  metal. 
The  portion  to  be  tinned  is  washed  with  alcohol  and  powdered  with 
sal-ammoniac,  and  those  surfaces  which  are  not  to  receive  the  lin¬ 
ing  metal  are  to  be  covered  with  a  clay  wash.  It  is  then  warmed 
sufficiently  to  volatilize  a  part  of  the  sal-ammoniac  and  tinned. 


ALLOYS  AND  AMALGAMS. 


91 


The  lining  is  next  cast  in  between  a  former,  which  takes  the  place 
of  the  journal  and  the  bearing. 

Fenton' s  Alloy  for  Axle-Boxes  for  Locomotives  and  Wagons. — 
Zinc,  80  parts;  copper,  5)4  ;  tin,  14)4.  This  alloy  may  be  recom¬ 
mended  as  regards  cheapness  and  lightness. 

De wrance' s  Patent  Bearing  for  Locomotives. — Copper,  4  parts  ; 
tin,  6  ;  antimony,  8. 

Alloy  for  Anti-Friction  Brasses. — Zinc,  80  parts;  tin,  14; 
copper,  5  ;  nickel,  1. 

Hoyle's  Patent  Alloy  for  Pivot  Bearings. — Tin,  24  parts;  lead, 
22  ;  antimony,  6.  It  is  claimed  to  stand  friction  without  heating 
longer  than  any  other  composition. 

Phosphor  Bronze,  which  is  largely  used  as  a  substitute  for  bronze 
and  gun-metal  compositions,  for  gearing,  bearings,  wire  rope,  etc., 
is  an  alloy  of  copper  and  tin,  which  has  been  fluxed  by  the  intro¬ 
duction  of  a  variable  quantity  of  phosphorus,  which  is  generally 
added  in  the  form  of  phosphide  of  copper  or  phosphide  of  tin. 
Phosphide  of  copper  is  prepared  by  heating  a  mixture  of  4  parts  of 
super-phosphate  of  lime,  2  parts  of  granulated  copper  and  1  part 
of  finely  pulverized  coal  in  a  crucible  at  not  too  high  a  temperature. 
The  melted  phosphide  of  copper,  which  contains  14  per  cent,  of 
phosphorus,  separates  on  the  bottom  of  the  crucible.  According 
to  another  method  phosphide  of  copper  is  prepared  by  adding 
phosphorus  to  copper  sulphide  solution  and  boiling,  adding  sul¬ 
phur  as  the  sulphide  is  precipitated.  The  precipitate  is  carefully 
dried,  melted  and  cast  into  ingots.  When  of  good  quality  and 
in  proper  condition  it  is  quite  black. 

Phosphide  of  Tin  is  prepared  as  follows  :  Place  a  bar  of  zinc  in 
an  aqueous  solution  of  chloride  of  tin,  collect  the  sponge-like  tin 
separated,  and  bring  it  moist  into  a  crucible,  upon  the  bottom  of 
which  sticks  of  phosphorus  have  been  placed.  Press  the  tin  tightly 
into  the  crucible  and  expose  it  to  a  gentle  heat.  Continue  the 
heating  until  flames  of  burning  phosphorus  are  no  longer  observed 
on  the  crucible.  After  the  operation  is  finished  a  coarsely-crystal- 
line  mass  of  a  tin-white  color,  consisting  of  pure  phosphide  of  tin, 
is  found  upon  the  bottom  of  the  crucible. 


92 


THE  METAL  WORKER’S  HANDY-BOOK. 


The  addition  of  phosphorus  to  bronze  prevents  the  formation 
of  oxide*-  by  which  the  strength,  ductility  and  homogeneity  of  the 
resulting  alloy  would  be  impaired,  and  furnishes  a  metal  which  in 
respect  to  these  qualities  is  notably  superior  to  ordinary  bronze. 
Numerous  grades  of  phosphor  bronze  are  made  according  to  the 
uses  for  which  it  is  intended.  However,  according  to  Thurston, 
five  sorts  are  considered  to  answer  all  requirements: 

o.  Ordinary  phosphor  bronze  of  2  per  cent,  phosphorus,  x. 
Good  phosphor  bronze  of  2 y2  per  cent,  phosphorus.  These  two 
numbers  are  in  all  cases  superior  to  ordinary  bronze  and  steel.  2. 
Superior  phosphor  bronze  of  3  per  cent,  phosphorus.  3.  Extra 
phosphor  bronze  of  3  */2  per  cent,  of  phosphorus.  4.  Maximum  phos¬ 
phor  bronze  of  4  per  cent,  of  phosphorus.  These  three,  according 
to  Delalot,  are  superior  to  any  other  bronzes.  Above  No.  4  phos¬ 
phor  bronze  is  useless ;  below  No.  o  it  is  inferior  to  common  bronze 
and  steel.  Nos.  3  and  4  are  comparatively  unoxidizable. 

Silicon-bronze  is  a  combination  of  copper  with  silicon;  its 
tenacity  is  as  great  as  that  of  phosphor-bronze,  and  its  power  of 
conducting  electricity  considerably  larger.  It  is  chiefly  used  for 
telephone-wires  which  with  the  same  conducting  power  have  only 
TV  the  weight  of  ordinary  wires.  The  following  shows  the  com¬ 
position  of  some  of  these  alloys: 


Telephone-wire  A. 


Copper . 99-94  per  cent. 

Tin . 0.03  “  “ 

Silicon .  0.02  “  “ 

Iron . trace  “  “ 

Zinc . . 


99.99  per  cent. 


Telegraph-wire  A. 


Copper .  97.12  per  cent. 

Tin .  1. 14  “  “ 

Silicon .  0.05  “  “ 

Iron . trace  “  “ 

Zinc . 1.62  “  “ 


99.93  per  cent. 


Silicon-brass. — Copper,  71.30  per  cent. ;  zinc,  26.65  >  lead, 
0.74;  tin,  0.57  ;  iron,  0.38;  silicon,  0.14. 

Statuary  Bronze. — The  bronze  at  present  used  for  statues  con¬ 
tains,  on  an  average,  copper,  86.6  per  cent.  ;  tin,  6.6;  lead,  3.3, 
and  zinc,  3.3.  A  statuary  bronze  which  thoroughly  answers  the 
purpose  must  become  thinly  fluid  in  fusing,  fill  the  moulds  out 
sharply,  allow  of  being  readily  worked  with  the  file,  and  must 


ALLOYS  AND  AMALGAMS. 


93 


acquire  a  beautiful  green  color,  the  patina,  on  exposure  to  the  air 
for  a  short  time.  Statuary  bronze  being  chiefly  used  for  artistic 
purposes,  its  color  is  of  great  importance. 

The  following  table  gives  a  series  of  alloys  of  different  colors  suit¬ 
able  for  the  purpose : 


Copper. 

Zinc. 

Tin. 

Color. 

84.42 

11.28 

4  3° 

red-yellow. 

84.00 

I  I. OO 

5.00 

orange-red. 

8305 

I3-03 

3-92 

<<  tf 

8300 

12.00 

5.00 

(t  it 

81.05 

15-32 

3-6  3 

orange-yellow. 

81.00 

15.00 

4-00 

a  a 

7809 

18.47 

3-44 

a  tt 

73-58 

23.27 

3-i5 

tt  tt 

73.00 

23.OO 

4.00 

pale-orange. 

70.36 

26.88 

2.76 

pale-yellow. 

70.00 

27.00 

3.00 

it  tt 

65-95 

31-56 

2.49 

In  the  following  table  will  be  found  the  compositions  of  a  few  cel¬ 
ebrated  statues ; 


Parts. 

<u 

eu 

a. 

0 

CJ 

Zinc. 

c 

p 

Lead. 

Iron. 

Nickel. 

Anti¬ 

mony. 

Column  Vendome  (Paris).. 

89.20 

0.5 

10.2 

0.1 

Column  of  July  (Paris)...  . 

91.40 

5.6 

1.6 

1.4 

Henry  IV.  (Paris) . 

89.62 

42 

5-7 

0.48 

Keller’s  Louis  XIV . 

91.4 

5-53 

i-7 

i-37 

Napoleon  I . 

75.0 

2.00 

3  0 

2.00 

The  Shepherd,  Potsdam 

Palace . 

88.68 

1.28 

9.2 

0.77 

Bacchus,  Potsdam  Palace.. 

89-34 

1.63 

7-5 

1. 21 

0.18 

Germanicus,  Potsdam . 

89.78 

2-35 

6  16 

i-33 

0.27 

Augsburg  bronze . 

8943 

8.17 

1.05 

0-34 

0.19 

94-74 

054 

1.64 

0.24 

0.71 

0.84 

Munich  bronze . 

77-03 

19.12 

C.9I 

2.29 

0.12 

0-43 

92.88 

0.44 

4.18 

2.31 

0.15 

94 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


Best  Bronze  for  Statiles  According  to  D' Arcet. — Copper,  78.5 
parts;  zinc,  17.2  ;  tin,  2.9;  and  lead,  1.4;  or,  copper,  164  parts; 
zinc,  36  ;  tin,  6 ;  and  lead,  3. 

Bronze  for  Gilding. — This  should  be  fusible  at  a  low  temperature, 
compact  and  close-grained.  Copper,  82.25  >  zinc,  17.50;  and  tin, 
0.25;  takes  gilding  well. 

Bronze  for  Small  Castings. — An  excellent  bronze  for  this  purpose 
is  composed  of  copper,  94.12  parts;  tin,  5.88.  It  becomes  very 
thinly  fluid  in  the  heat  and  fills  out  the  moulds  well. 

Bronze  which  can  be  Rolled. — A  bronze  containing  4.5  to  7  parts 
of  tin  to  100  of  copper  can  be  readily  rolled  out  to  sheets  at  a  red 
heat. 

Chinese  Bronzes. — Analyses  of  different  specimens  of  Chinese 
bronze  gave  the  following  results: 


Name. 

Parts. 

I. 

II. 

III. 

Tin . 

4-36 

5-52 

7.27 

C  opper . 

82.72 

72.09 

72.32 

Lead . 

9-9 

20.31 

14-59 

Iron . 

°-55 

1  -73 

0.28 

Zinc . 

1  86 

Arsenic . 

trace 

trace 

Delta-metal  is  an  alloy  of  zinc,  iron  and  copper,  which  receives 
during  fusing  an  addition  of  phosphorus  and,  according  to  the 
desired  properties,  a  further  addition  of  tin,  manganese  and  lead. 
It  has  the  color  of  a  gold-silver  alloy,  and  can  be  worked  cold  as 
well  as  hot ;  it  cannot  be  welded  ;  with  some  care  it  may,  however, 
be  soldered.  It  does  not  rust.  On  account  of  its  great  tenacity  it 
is  used  in  place  of  steel  for  torpedoes,  bicycles,  ship-chains,  in  the 
construction  of  steamboats,  etc. 

Delta-metal  as  manufactured  by  the  “ Deutsche  Della-Mctall 
Gesellschaft '  ’  is  composed  as  follows  : 


ALLOYS  AND  AMALGAMS. 


95 


Name 

Cast. 

Wrought. 

Rolled. 

Hot  punched. 

Copper . . 

Lead . 

Iron . 

Manganese . 

Zinc . 

Nickel . 

Phosphorus . 

Per  cent. 

55-94 

0.72 

0  87 

0.81 

41.61 

trace 

0.013 

Per  cent. 
55.80 

1.82 

1.28 

0.96 

40.07 

trace 

O.OI  1 

Per  cent. 
55.82 

0.76 

0.86 

1.38 

41.41 

0.06 

trace 

Per  cent. 
54.22 

1. 10 

0.99 

1.09 

42.25 

0. 16 

0.02 

99963 

99.941 

100.29 

99-83 

Gold  Bronze.— Copper,  90.5  parts;  tin,  6.5;  zinc,  3.  This 
alloy  retains  its  beautiful  gold  color  on  exposure  to  the  air,  but 
loses  it  rapidly  if  exposed  to  both  air  and  water. 

Japanese  Bronze. — M.  E.  J.  Maumene  gives  the  results  of  an 
analysis  of  Japanese  bronzes  as  follows  : 


Name. 

Parts. 

L 

II. 

III. 

IV. 

Copper . 

86.38 

80.91 

88.70 

92.07 

Tin . 

1.94 

7-55 

2.58 

I.04 

Antimony . 

I.6l 

0.44 

O.IO 

I.04 

Lead . 

5.68 

5-33 

3-54 

I.04 

Zinc . 

3- 36 

3.08 

3-71 

2.65 

Iron . 

0.67 

i-43 

1.07 

3-64 

Manganese . 

0.67 

trace 

1.07 

3-64 

Silicic  acid . 

O.IO 

0.16 

0.09 

O.O4 

Sulphur . 

O.IO 

0.31 

O.O9 

O.O4 

Waste . 

0.26 

0.79 

0.21 

0.56 

Malleable  Bronze. — A  patent  has  been  taken  out  both  in  England 
and  France  by  Messrs.  A.  Sentex,  C.  Marshall  and  A.  Saunier,  es¬ 
tablishing  a  process  for  producing  malleable  and  ductile  bronze  bars 
or  plates  which  are  free  from  cracks  and  blow-holes,  are  “  un- 
oxidizable”  and  which  may  be  “  rolled  and  drawn  with  the  greatest 
ease,”  and,  moreover,  have  the  appearance  and  “sonorousness  of 


96 


THE  METAL  WORKER’S  IIANDY-BOOK. 


gold:”  3.3  lbs.  of  tin  are  purified  by  melting  under  nitre;  22 
lbs.  of  copper  are  melted  and  1.76  ozs.  of  equal  parts  of  nitrate 
and  cyanide  of  potassium  are  added  for  the  double  purpose  of  re¬ 
ducing  the  oxides  and  “  fattening  ”  the  metal.  Then  0.88  oz.  of 
bitartrate  of  potassium  with  the  same  quantity  of  cyanide  is  added, 
and,  after  poling,  the  tin  is  introduced;  0.88  oz.  each  of  sal-am¬ 
moniac  and  cyanide  are  thrown  on  ;  15.43  grains  of  “  phosphuret 
of  copper”  introduced  to  “impart  mildness,”  and  0.7  oz.  of 
“Marseilles  soap”  added,  which  still  further  fattens  the  metal. 
Finally  15.43  grains  of  sodium  are  added  at  the  moment  of 
casting.  The  metal,  if  cast  in  sand,  may  contain  zinc,  and,  the 
portion  of  tin  reduced,  the  quantity  of  phosphorus  and  sodium 
may  be  increased. 

O Id  Peruvian  Bronze. — An  old  chisel,  weighing  about  7  ozs., 
found  in  Quito,  showed,  according  to  Boussingault,  the  following 
composition:  Copper,  95  parts;  tin,  4.5;  lead,  0.2;  iron,  0.3; 
silver,  traces. 

Ormolu. — This  bronze  is  distinguished  by  a  pure  golden-yellow 
color  and  requires  but  very  little  gold  for  gilding.  It  is  much  used 
for  the  finest  bronze  articles  of  luxury.  It  is  composed  of  copper, 
58.3  parts;  tin,  16.7;  zinc,  25.3. 

Silveroid. — This  alloy,  which  has  been  recently  brought  into 
commerce  by  H.  Wiggin,  consists  of  copper  and  nickel,  to  which, 
according  to  the  purpose  for  which  it  is  intended,  zinc,  tin  and 
lead  are  added.  The  alloy  is  very  white,  lustrous,  fine-grained  and 
of  great  tenacity.  It  is  used  as  a  substitute  for  gun-metal  and 
brass  where  a  lustrous  color  and  polish  are  required. 

Speculum-metal. — The  alloys  known  under  this  name  are  em¬ 
ployed  for  making  metallic  reflectors,  requiring  a  true  white  color, 
good  lustre  and  a  hard,  clean  surface  not  easily  tarnished  or 
scratched.  Speculum-metal  contains  on  an  average  from  64  to  69 
per  cent,  of  copper  and  30  to  35  per  cent,  of  tin.  To  heighten 
the  white  color  small  quantities  of  arsenic  and  antimony  are  some¬ 
times  added. 

The  following  table  shows  the  composition  of  some  alloys  used 
for  speculum-metal : 


ALLOYS  AND  AMALGAMS. 


97 


Name. 

Parts. 

Copper. 

Tin. 

Zinc. 

Arsenic. 

Other  metals. 

Standard  alloy . 

68.21 

31-79 

Otto’s . 

68.5 

31-5 

Richardson’s . 

65-3 

3° 

0.7 

2 

2  Silver. 

Mudge’s . 

65 

35 

Little’s . 

65 

30.8 

2-3 

i-9 

Sallit’s . 

64.6 

31-3 

4.1  nickel. 

Chinese . 

80.83 

8.5  antimony. 

Old  Roman . 

6  3-9 

19.05 

17.29  lead. 

Alloys  of  Copper  and  Zinc.  Brass  and  Si?nilar  Alloys. — Brass  is 
an  alloy  of  copper  and  zinc  in  varying  quantities.  Ordinary  brass 
contains  from  18  to  50  per  cent,  of  zinc  (on  an  average  to  2  parts 
of  copper  1  part  of  zinc).  With  a  larger  content  of  copper 
the  color  becomes  reddish  and  the  alloy  is  called  tombac.  Tombac 
contains  at  the  utmost  18  per  cent,  of  zinc;  it  is  especially  used 
where  great  ductility,  flexibility  and  but  little  hardness  are  required, 
as,  for  instance,  for  fine  works  of  wire  and  sheet,  or  where  a  reddish 
shade  of  color  is  desired,  for  instance,  for  articles  which  are  to  be 
gilded.  For  most  technical  purposes,  however,  brass  richer  in 
zinc  is  employed,  mostly  because,  on  account  of  the  greater  content 
of  zinc,  it  is  cheaper  and  besides  more  readily  fusible.  Brass 
for  ordinary  coarser  castings  consists  generally  of  alloys  with  a 
high  content  of  zinc,  which,  besides,  are  frequently  produced  from 
the  more  impure  raw  materials.  But  brass  for  the  fabrication  of 
sheet  and  wire  is  made  from  the  purest  materials  and  contains  less 
zinc  than  cast-brass,  generally  from  25  to  35  per  cent.,  exception¬ 
ally  only  up  to  37  per  cent.  Besides  copper  and  zinc,  brass  fre¬ 
quently  contains  very  small  quantities  of  other  metals  (tin,  lead, 
iron),  which  are  seldom  intentionally  added,  but  mostly  come  from 
impurities  of  the  component  metals.  The  color  of  copper-zinc 
alloys  varies  according  to  the  content  of  tin  and  will  be  seen  from 
the  following  table : 

7 


98 


THE  METAL  WORKER’S  HANDY-BOOK. 


Color  of  Copper-Zinc  Alloys. 


Content  of 
zine. 

Color. 

Content  of 
zinc. 

Color. 

5  per  cent . 

35  per  cent.  . 

IO  “  . 

38  “ 

.  .  .dark  yellow. 

16  “  . 

. red-yellow. 

41 

. .  reddish-yellow. 

20  “  . 

. .  . .  reddish-yellow. 

50  “ 

22  “  . 

60  “  . . . 

25  “  . 

70  “ 

27  “  . 

80  “ 

30  “  . 

90  “ 

To  brass  belong  also  a  number  of  copper-zinc  alloys  for  definite 
purposes  ;  for  instance,  Aich’s  metal,  oroide,  etc.,  the  composition 
of  which  is  given  in  the  following  table : 


Composition  of  Copper-Zinc  Alloys. 

I.  Tombac  {Red  Brass )  and  Similar  Alloys , 


Name. 

Copper 

Zinc. 

Tin. 

Lead. 

Various 

metals. 

Tombac,  from  Ocker . 

85 

15 

“  “  Iserlohn . 

92 

8 

“  “  Hegermuhle . 

853 

14.7 

English  tombac  for  castings . 

86.4 

13.6 

Tombac  for  fine  sharp  castings . 

87 

13 

“  “  gun  mountings . 

80 

17 

3 

Ntirnberg  tombac  for  Dutch  gold. . 

84.6 

•5-4 

Tombac  for  jewelry  (chrysochalk) 

90 

7-9 

Tombac  resembling  gold . 

89.97 

9.96 

0.05 

“  “  “  . 

82 

'7-5 

o-5 

Tombac  for  gilding . 

86 

14 

“  (d’Arcet) . 

82.5 

17-5 

Sheet  for  buttons . 

99-15 

0.85 

it  it  tt 

84.21 

15-79 

Austrian  axle  journals . 

92.5 

7-5 

Pinchbeck  for  fancy  articles . 

93-6 

6.4 

Oroide . 

90 

IO 

“  . 

S5.5 

14-5 

Talmi  gold . 

86.4 

12.2 

1. 1 

0.3  iron. 

Similor  or  Mannheim  gold.  . 

89.44 

9-93 

0.62 

Tournay’s  metal  (for  buttons) . 

S2.54 

17.46 

Tissier’s  metal  (very  hard) . 

97 

2 

1  to  2  arsenic. 

ALLOYS  AND  AMALGAMS. 


99 


Composition  of  Copper- Zinc  Alloys — Continued. 
II.  Brass  and  Similar  Alloys. 


Name. 

Copper 

Zinc. 

Tin. 

Lead. 

Various  metals. 

Sheet  brass  from  Stollberg . 

“  “  Hegermiihle.  . 

u  “  Ocker . 

64.8 

70.16 

68.98 

70.1 
72-73 

68.1 

32.8 
2745 

29-54 

29.9 
27.27 
3i  9 
337 

38.2 

40 

29.2 
27.63 

27  45 
28.15 

28.5 

34- 6 

324 

24.42 

37-2 
36.88 
31.46 
33  5 
324 

35- 5 
27.27 

33-4 

38.2 

28 

33-3 

24.9 
33-i 
44-5 

46 

45.1 

24-5 

32.8 

39-2 

347 

0.4 

0.2 

2.0 

0.79 

0.97 

f  0.79  antimony. 

“  “  Iserlohn . 

“  "  Liidenscheid... 

6t  t(  Vienna . . 

\  0.23  iron. 

“  “  Temappes . 

((  “  China . 

64.4 

56.6 

60 

0.2 

3-3 

1.4 

1.0 

1.4  iron. 

“  for  ships’  sheathing, 

so-called  Muntz  metal . 

Brass  wire  from  England . 

70.3 

71.89 

70.16 

7136 

71-5 

654 

65-S 

71.88 

62.2 

0.2 

o-3 

0.85 

0.2 

“  “  Augsburg . 

“  “  Neustadt . 

«  it  it 

it  it  it 

“  good  quality . 

0.79 

“  brittle . 

2.1 

Cast  brass  from  Ocker . 

1.09 

°-5 

0.88 

o-3 

2.9 

(  2.32  iron 

a  a  a 

\  1. 01  antimony. 
0. 1  iron. 

Clock  wheels  (Black  Forest)  . . 

ti  it  if  it 

Turned  castings  from  Iserlohn.. 

tt  it  a  a 

Cast  brass  for  stamps  used  for 
gilding  in  book-binderies.  .  .  . 
Brass  from  Liidenscheid . 

60.66 
60  06 
637 

64.5 

61.6 

72  73 

66.6 

1- 35 

2- 5 
0.2 

0.74  iron. 

I.43  iron. 

3.0  antimony. 

a  <t 

Aich  or  sterro-metal  malleable 
in  the  heat . 

60 

1.8  iron. 

Chrysorin,  for  fancy  articles..  .. 

“  (by  Rauchenberger). 

Potin,  brittle,  ordinary  brass..  .. 
English  sterling  metal . 

72 

66.7 

71.9 

66.2 

1.2 

2.0 

0.7  iron. 

Thurston’s  tough,  strong  brass... 
Brass,  very  tenacious  (Storer).  . 

if  if  ti  it 

Bristol  brass  (Prince’s  metal).  . 

it  ft  ti  tt 

if  tt  ft  it 

Mosaic  gold . 

55 

54 

54-9 

75-5 

67.2 

608 

65-3 

0.5 

100 


THE  METAL  WORKER’S  HANDY-BOOK. 


Composition  of  Copper-Zinc  Alloys — Continued. 


II.  Brass  and  Similar  Alloys. 


Name. 

Copper 

Zinc. 

Tin. 

Lead. 

Various  metals. 

Sheet  from  manganese  bronze, 

J 

1. 13  iron. 

pale  yellow . 

60.95 

29-93 

1 

7.95  manganese 

Sheet  from  manganese  bronze, 

J 

4.48  manganese 

still  paler . 

63.16 

26.  n 

.... 

1 

3.67  nickel. 

Cast  brass, French, for  fine  castin’s 

63.70 

33  55 

2.50 

0.2; 

ft  ft  (f  if 

64.45 

32-44 

0.25 

2.86 

ft  u  u  ft 

70.90 

24  05 

2.00 

3  05 

t  ft  if  tt  a 

7243 

22.75 

1.87 

2.95 

Robierre’s  metal,  for  ship  sheath- 

ing . 

66 

34 

Sterro-metal  (Rosthorn’s) . 

55-33 

41. So 

4.66  iron. 

“  (English  or  Ged- 

ge’s  alloy  for  ship-sheathing). 

60 

3S.5 

1.5  iron. 

Alloys  of  Copper  with  Silver  and  Gold. — On  account  of  their 
great  intrinsic  value  these  alloys  are  chiefly  used  for  coinage  and  in 
art  industries.  At  the  present  time  the  fineness  of  all  coins  is 
determined  by  thousandths,  the  standard  varying  according  to  the 
size  of  the  coins,  and  the  laws  of  the  different  countries  from  T9o°0°0- 
to  TVoV  The  fineness  used  in  the  manufacture  of  silverware  varies 
from  to  T9cny0c>>  while  that  of  gold  ware  varies  from  to 

t9<jo°o>  ordinary  Pforzheim  gold  articles  containing,  for  instance, 
only  from  ^  to  &%%■ 

Color  of  Gold  Alloys. — The  color  of  gold  alloys  depends  on  the 
greater  or  smaller  contents  of  gold  and  silver.  Alloys  very  rich  in 
silver  are  more  whitish,  and  those  very  rich  in  copper  more  red¬ 
dish.  Cadmium  imparts  a  green  color,  and  steel  a  gray  color  to 
the  alloy.  The  following  table  gives  the  composition  of  colored 
gold  alloys  most  used  : 


ALLOYS  AND  AMALGAMS. 


101 


Color. 

Parts. 

Gold. 

Silver. 

Copper. 

Cadmium. 

Steel. 

Yellow . 

583 

250 

167 

Dark  yellow . 

583 

125 

292 

Very  red . 

583 

42 

375 

Yellow. . . 

666 

194 

i39 

Red . 

666 

67 

268 

Yellow . 

750 

146 

104 

Red . 

750 

104 

146 

Green . 

750 

166 

84 

<< 

746 

1 14 

97 

43 

“  . . 

750 

I25 

.... 

125 

Gray . 

800 

.... 

200 

(C 

725 

275 

(t 

857 

86 

.... 

.... 

57 

Blue . 

250  to  750 

.... 

.... 

25° 

Pale  yellow . 

666 

333 

Pale  red . 

600 

200 

200 

Proportion  of  Various  Metals  in  Gold  Alloys  used  by  Jewellers. 


Carats. 

Parts. 

Melts  at  degrees  F. 

Copper. 

Silver. 

Gold. 

23 

X 

X 

23 

2012 

22 

I 

I 

22 

2009 

20 

2 

2 

20 

2002 

18 

3 

3 

18 

1995 

15 

6 

3 

15 

1992 

>3 

8 

3 

13 

1990 

12 

8^ 

3^ 

12 

1987 

IO 

IO 

4 

IO 

1982 

9 

4^ 

9 

1979 

8 

10  yh. 

5  Yz 

8 

1973 

7 

9 

8 

7 

i960 

Argent-Ruolz. — This  alloy,  also  called  argent  franeais,  has  the 
appearance  of  pure  silver  but  is  much  cheaper  and  harder. 


102 


THE  METAL  WORKER’S  H ANDY-BOOK. 


According  to  the  quality  of  the  articles,  different  alloys  are  used 
as  follows : 

Parts. 


I.  II.  III.  ' 

Silver . .  33  40  20 

Copper .  37  to  42  30  to  40  45  to  55 

Nickel .  25  to  30  20  to  30  25  to  35 


Gray  Silver  {Japanese  Silver). — In  Japan  an  alloy  of  equal  parts 
of  silver  and  copper  is  prepared  which  acquires  a  beautiful  gray 
color  by  boiling  in  a  solution  of  alum  to  which  sulphate  of  copper 
and  verdigris  are  added. 

Tiers  Argent  ( one-third  Silver). — Silver  33.33  parts,  aluminium 
66.66.  Used  in  Paris  for  the  manufacture  of  various  utensils.  It 
is  harder  than  silver,  and  stamped  and  engraved  with  greater  ease 
than  alloys  of  copper  and  silver. 

Imitation  Silver  Alloys. — There  is  a  large  number  of  imitation 
silver  alloys  which  are  used  as  substitutes  for  many  purposes.  The 
composition  of  a  few  of  them  is  here  given  : 

Alloy  for  Spoons. — A  beautiful  alloy  closely  resembling  silver  is 
obtained  by  melting  together  copper,  50  parts;  nickel,  25,  and 
zinc,  25. 

Alloy  resembling  Silver. — Copper,  70  parts;  manganese,  30; 
zinc,  20  to  25. 

Delalot' s  Alloy. — Pure  copper,  80  parts;  manganese,  2;  zinc, 
18;  phosphate  of  lime,  1.  First  melt  the  copper,  then  add 
gradually  the  manganese  and,  when  this  is  completely  dissolved, 
the  phosphate  of  lime.  Remove  the  scoria  and  about  ten  minutes 
before  casting  add  the  zinc.  To  promote  the  fusion  of  the  man¬ 
ganese,  part  of  calcium  fluoride,  part  of  borax  and  1  part  of 
charcoal  may  be  added. 

Mousset' s  Silver  Alloy. — Copper,  59.06  parts;  silver,  27.56; 
zinc,  9.57  ;  nickel,  3.42.  Color,  yellowish  with  a  reddish  tinge, 
but  white  upon  the  fractured  surface. 

IVarne' s  Metal. — Tin,  10  parts;  nickel,  7;  bismuth,  7;  cobalt,  3. 
White,  fine-grained,  quite  difficult  to  fuse. 


ALLOYS  AND  AMALGAMS. 


103 


White  Alloy  Closely  Resembling  Silver. — Copper,  69.8  parts; 
nickel,  19.8;  zinc,  5.5  ;  cadmium,  4.7. 

Aluminium  Alloys.  1.  Aluminium  Brasses. — By  this  name  are 
generally  known  the  alloys  of  aluminium  with  zinc  and  copper  ; 
they  are  about  as  much  superior  to  ordinary  brass  as  aluminium 
bronze  is  to  ordinary  bronze.  They  are  made  in  two  general 
ways;  either  by  introducing  metallic  aluminium  into  melted  brass 
or  by  introducing  zinc  into  melted  aluminium  bronze.  Repeated 
remeltings  of  aluminium  brass  are  not  advisable,  since,  like  all 
brasses,  it  changes  its  composition  on  melting,  though  not  to  so 
large  a  degree.  After  mixing  it  needs  to  be  remelted  only  once  in 
a  clean  crucible.  Aluminium  brasses  flow  well,  give  sharp  sound 
castings,  are  more  ductile,  malleable,  and  have  greatly  increased 
strength  and  power  to  resist  corrosion. 

Cowles  Bros,  report  the  following  series  of  tests  made,  in  1886, 
at  their  works  in  Lockport,  their  alloys  all  being  made  by  adding 
zinc  to  alu?niniu7n  bronze : 


Composition. 

Tensile  strength  per 
square  inch  (cast¬ 
ings). 

Elongation 
per  cent. 

Aluminium. 

Copper. 

Zinc. 

5-8 

67.4 

26.8 

95.712 

1.0 

3-3 

633 

33-3 

85.867 

7.6 

3-o 

67.0 

30.0 

67-34I 

12.5 

i-5 

77-5 

21.0 

32-356 

41.7 

*•5 

71.0 

27-5 

4I-952 

27.0 

1.25 

70.0 

28.0 

35-059 

25.0 

2-5 

70.0 

27.5 

40.982 

28.0 

1.0 

57-o 

42.0 

68.218 

2.0 

1. 15 

55-8 

48.0 

69.520 

4.0 

When  it  is  remembered  that  ordinary  brass  has  rarely  a  tensile 
strength  of  over  30,000  lbs.  with  an  elongation  of  about  10  per 
cent.,  the  benefit  of  the  aluminium  can  be  easily  realized.  The 
principal  disadvantage  of  aluminium  brass  compared  with  alumin- 


104 


THE  METAL  WORKER’S  HANDY-BOOK. 


ium  bronze  is  that  it  cannot  be  remelted  without  changing  its 
quality  by  reason  of  its  containing  zinc. 

2.  Aluminium  Bronze. — Aluminium  possesses  properties  which 
render  it  one  of  the  most  useful  metals  yet  discovered,  and  the 
only  bar  to  its  greater  employment  has  hitherto  been  its  high  price. 
At  the  present  time  strenuous  efforts  are  made  to  cheapen  the 
manufacture  of  the  metal,  and  there  is  an  immediate  prospect  of 
the  price  being  considerably  reduced  by  various  new  processes. 
While  being  very  malleable  and  ductile,  aluminium  ranks  second 
only  to  steel  in  tenacity;  it  is  highly  sonorous,  four  times  lighter 
than  silver,  non-volatile  at  very  high  temperatures,  conducts  heat 
and  electricity  as  well  as  silver,  is  inoxidizable  in  the  air  even  at  a 
red  heat,  is  not  acted  upon  by  water,  sulphuretted  hydrogen  or 
ammonium  sulphide,  resists  concentrated  nitric  acid  and  dilute 
sulphuric  acid,  and  forms  alloys  of  considerable  value. 

The  alloys  of  aluminium  with  copper  show  very  different  proper¬ 
ties  according  to  the  quantities  of  aluminium  they  contain.  Alloys 
containing  but  little  copper  cannot  be  used  for  industrial  purposes. 
With  60  to  70  per  cent,  of  aluminium  they  are  very  brittle,  glass- 
hard  and  beautifully  crystalline.  With  50  per  cent,  the  alloy  is 
quite  soft,  but  under  30  per  cent,  of  aluminium  the  hardness 
returns. 

The  usual  alloys  are  those  of  1,  2,  5  and  10  per  cent,  of  alumin¬ 
ium.  The  5  per  cent,  bronze  is  golden  in  color,  polishes  well, 
casts  beautifully,  is  very  malleable,  cold  or  hot,  and  has  great 
strength,  especially  after  hammering.  The  7.5  per  cent,  bronze  is 
to  be  recommended  as  superior  to  the  5  per  cent,  bronze.  It  has  a 
peculiar  greenish-gold  color  which  makes  it  very  suitable  for 
decoration.  All  these  good  qualities  are  possessed  by  the  10  per 
cent,  bronze.  It  is  bright  golden,  keeps  its  polish  in  the  air,  may 
be  easily  engraved,  shows  an  elasticity  much  greater  than  steel, 
and  can  be  soldered  with  hard  solder. 

In  making  aluminium-copper  alloys  great  attention  must  be  paid 
to  the  quality  of  the  copper  used.  Ordinary  commercial  copper 
may  contain  small  amounts  of  antimony,  arsenic  or  iron,  which  the 
aluminium  can  in  no  way  remove  and  which  effect  very  injuriously 


ALLOYS  AND  AMALGAMS. 


105 


the  quality  of  the  bronze.  The  aluminium  bronzes  seem  to  be 
extremely  sensitive  to  the  above  metals,  particularly  to  iron.  This 
necessitates  the  employment  of  the  purest  copper;  electrolytic  is 
sometimes  used  when  not  too  high-priced,  but  Lake  Superior  is 
generally  found  satisfactory  enough.  Even  the  purest  copper  may 
contain  dissolved  cuprous  oxide  or  occluded  gases,  and  it  is  one  of 
the  functions  of  aluminium  to  reduce  these  oxides  and  gases, 
forming  slag  which  rises  to  the  surface  and  leaving  the  bronze  free 
from  their  influences.  If  tin  occurs  in  the  copper  it  lowers  very 
greatly  the  ductility  and  strength  of  the  bronzes,  but  zinc  is  not  so 
harmful. 

Care  should  also  be  taken  as  to  the  purity  of  the  aluminium  used, 
though  its  impurities  are  not  so  harmful  as  they  would  be  if  occur¬ 
ring  in  similar  percentage  in  copper,  since  so  much  more  copper 
than  aluminium  is  used  in  these  alloys.  Yet  the  bronzes  are  so 
sensitive  to  the  presence  of  iron  that  an  aluminium  with  as  small  a 
percentage  of  this  metal  as  possible  should  be  used.  The  silicon 
in  commercial  aluminium  is  not  so  harmful  as  the  iron,  but  it  does 
harden  the  bronze  considerably  and  increases  its  tensile  strength. 
The  purest  aluminium  alloyed  with  the  purest  copper  always  pro¬ 
duces  the  highest  quality  of  bronze. 

The  following  directions  for  preparing  the  bronzes  are  given  : 
Melt  the  copper  in  a  plumbago  crucible  and  heat  it  somewhat 
hotter  than  its  melting  point.  When  quite  fluid  and  the  surface 
clean,  sticks  of  aluminium  of  a  suitable  size  are  taken  in  tongs  and 
pushed  down  under  the  surface,  thus  protecting  the  aluminium  from 
oxidization.  The  first  effect  is  necessarily  to  chill  the  copper  more 
or  less  in  contact  with  the  aluminium,  but  if  the  copper  was  at  a 
good  heat  to  start  with,  the  chilled  part  is  speedily  dissolved  and 
the  aluminium  attacked.  The  chemical  action  of  the  aluminium 
is  then  shown  by  a  rise  of  temperature,  which  may  even  reach  a 
white  heat.  Considerable  commotion  may  take  place  at  first,  but 
this  gradually  subsides.  When  the  required  amount  of  aluminium 
has  been  introduced,  the  bronze  is  let  stand  for  a  few  minutes  arid 
then  well  stirred,  taking  care  not  to  rub  or  scrape  the  sides  of  the 
crucible.  By  the  stirring  the  slag,  which  commences  to  rise  even 


TITE  METAL  WORKER’S  IIANDY-BOOK. 


10G 

during  the  alloying,  is  brought  almost  entirely  to  the  surface.  The 
crucible  is  then  taken  out  of  the  furnace,  the  slag  removed  from 
the  surface  with  a  skimmer,  the  melt  again  stirred  to  bring  up  what 
little  slag  may  still  remain  in  it,  and  is  then  ready  for  casting.  It 
is  very  injurious  to  leave  it  longer  in  the  fire  than  is  absolutely 
necessary.  No  flux  is  necessary,  the  bronze  needing  only  to 
be  covered  with  charcoal  powder.  The  particular  point  to  be  at¬ 
tended  to  in  melting  these  bronzes  is  to  handle  as  quickly  as  pos¬ 
sible  when  once  melted. 

As  with  ordinary  brass  and  bronze  two  or  three  remeltings  are 
needed  before  the  combination  of  the  metal  appears  to  be  perfect 
and  the  bronze  takes  on  its  best  qualities.  After  three  or  four 
meltings  it  reaches  a  maximum  at  which  point  it  may  be  melted 
several  times  without  sensible  change.  It  gives  good  castings  of 
all  sizes  and  runs  in  sand  moulds  very  uniformly.  Its  specific 
gravity  is  7.68,  about  that  of  soft  iron.  Its  strength  when  ham¬ 
mered  is  equal  to  the  best  steel.  It  may  be  forged  at  about  the 
same  heat  as  cast-steel  and  then  hammered  until  it  is  almost  cold 
without  breaking  or  ripping.  Tempering  makes  it  soft  and  malle¬ 
able.  It  does  not  foul  a  file  and  may  be  drawn  into  wire.  Any 
part  of  a  machine  which  is  usually  made  of  steel  can  be  replaced 
by  aluminium  bronze. 

Ferr o-aluminium. — The  iron-aluminium  alloy  known  by  this 
name,  which  is  being  largely  used  at  present  for  introducing 
into  iron  and  steel,  is  generally  made  with  5  to  15  per  cent, 
of  aluminium.  Several  different  makes  of  this  alloy  are  on  the 
market,  some  made  directly  from  alumina,  others  made  by  adding 
aluminium  to  iron.  When  made  by  the  latter  method  a  good 
quality  of  pig-iron  is  chosen,  and  when  melted  the  aluminium, 
in  bars,  is  seized  in  tongs  and  dipped  under  the  surface.  A  rise 
of  temperature  occurs,  and  a  noticeable  separation  of  graphitic 
carbcn,  causing  “  kish  ”  to  collect  on  the  surface.  It  is  said  that 
the  pig-iron  thus  alloyed  has  its  combined  carbon  almost  entirely 
converted  into  free  carbon,  losing  thereby  in  weight  sometimes  as 
much  as  2^4  per  cent.  When  all  the  aluminium  required  has 
been  added  the  melt  is  stirred,  the  crucible  remaining  in  the  fur- 


ALLOYS  AND  AMALGAMS. 


107 


nace ;  then  it  is  let  stand  for  a  few  minutes,  taken  out  of  the  fire, 
skimmed  clean  and  cast  into  slabs  or  bars. 

Various  Aluminium  Alloys. — The  following  alloys  have  been 
patented  by  Mr.  Jas.  Webster : 

I.  Copper  is  melted  and  aluminium  added  to  it  until  a  io  per 
cent,  bronze  is  made.  There  is  then  added  to  it  i  to  6  per  cent, 
of  an  alloy,  ready  prepared,  containing  :  Copper,  20  parts  ;  nickel, 
20  ;  tin,  30  ;  aluminium,  7. 

II.  The  two  following  alloys  are  prepared  in  the  usual  way,  under 
a  flux  consisting  of  equal  parts  of  potassium  and  sodium  chlorides, 
and  are  cast  into  bars. 


Aluminium . 15  parts. 

Tin . 85  “ 


II. 

Nickel .  17  parts. 

Copper .  17  “ 

Tin . 100  “ 


To  make  the  bronzes  equal  parts  of  these  two  alloys  are 
melted  with  copper,  the  more  of  the  alloys  used  the  harder  and 
better  the  bronze.  The  best  mixture  is,  of  copper,  84  parts ;  al¬ 
loy  I.,  8;  alloy  II.,  8.  The  copper  is  first  melted,  then  the  al¬ 
loys  put  in  together  and  stirred  well  with  a  stirrer  of  wood  or  clay. 
This  alloy  is  suitable  for  art  castings,  kitchen  utensils,  etc.,  or  any¬ 
where  where  durability,  hardness,  malleability,  polish  and  very 
slight  oxidizability  are  required.  A  cheaper  and  more  common 
alloy  may  be  made  of  copper,  91  parts;  alloy  I.,  4;  alloy  II.,  5. 

III.  The  following  alloy  is  said  to  withstand  oxidation  well,  to 
have  great  tenacity,  durability,  capability  to  bear  vibrations  and  to 
take  a  high  polish.  A  preliminary  alloy  is  made  of  copper,  200 
parts;  tin,  80;  bismuth,  10;  aluminium,  10.  The  alloy  proper  is 
formed  by  melting  together  :  Preliminary  alloy,  4 y  parts  ;  copper, 
164;  nickel,  70;  zinc,  6i}4- 

IV.  Copper,  53  parts ;  nickel,  22^  zinc,  22  ;  tin,  5  :  bis¬ 
muth,  ;  aluminium,  y. 

Alloy  for  Dental  Plates. — Aluminium,  90  to  93  parts  ;  silver,  5 
to  9  ;  copper,  1.  This  alloy,  when  cast  under  slight  pressure,  gives 
perfect  castings,  is  very  white  and  easy  to  work.  The  addition  of 


108 


THE  METAL  WORKER’S  HANDY-BOOK. 


copper  is  said  to  decrease  to  a  minimum  the  shrinkage  of  the  alloy, 
also  giving  a  closer  grain. 

Alloy  Resembling  German  Silver. — Copper,  70  parts;  nickel,  23; 
aluminium,  7.  This  alloy  has  a  beautiful  white  color  and  takes  a 
high  polish.  It  resembles  some  of  the  finer  grades  of  German 
silver. 

Alloy  Resembling  Silver. — Copper,  75  parts;  nickel,  16;  zinc, 
2 ;  tin,  2 ;  cobalt,  2  ;  iron,  1  y2  ;  aluminium, 

Bourbonne' s  Aluminium  Alloy. — For  many  purposes  this  alloy 
may  serve  as  a  substitute  for  aluminium.  It  is  obtained  by  melting 
together  10  parts  of  tin  and  10  of  aluminium.  It  is  whiter  than 
aluminium,  has  a  specific  gravity  of  2.05  (is,  therefore,  somewhat 
heavier  than  the  pure  metal),  is  more  capable  than  aluminium  of 
resisting  most  agents  and  is  worked  with  greater  ease.  Finally  the 
alloy,  without  previous  preparation,  can  be  soldered  as  readily  as 
brass. 

Leches ne. — Under  this  name  two  compositions  have  been  pat¬ 
ented  in  England  : 


I.  II. 

Copper .  900  parts.  600  parts. 

Nickel .  100  “  400  “ 

Aluminium .  “  lA  “ 


The  first  of  these  alloys  is  the  one  to  which  the  name  “Lechesne  ” 
appears  to  be  given.  It  is  made  by  putting  first  the  nickel  into 
the  crucible  and  after  melting  gradually  stirring  in  the  copper.  The 
heat  is  then  raised  and  the  aluminium  added.  The  alloy  is  heated 
almost  to  boiling  and  cast  very  hot.  It  is  claimed  that  this  alloy 
is  equal  to  the  finest  German  silver. 

Minargent. — Copper,  100  parts;  nickel,  70;  antimony,  5; 
aluminium,  2.  It  is  similar  to  the  alloy  resembling  German  sil¬ 
ver,  but  somewhat  harder.  Melt  together  the  copper,  nickel 
and  antimony,  and  then  granulate  the  resulting  alloy  in  water. 
The  dried  granules  are  mixed  with  the  aluminium  and  with  1.5  per 
cent,  of  a  flux  consisting  of  2  parts  borax  and  1  part  fluorspar,  and 
then  remelted. 

Neogen. — Copper,  58  parts;  zinc,  27;  nickel,  12;  tin,  2;  bis- 


ALLOYS  AND  AMALGAMS. 


109 


muth,  y?  ;  aluminium,  y2.  This  alloy  is  claimed  to  closely  re¬ 
semble  silver. 

Nurnberg  Gold. — Copper,  90  per  cent.  ;  gold,  2 y2  ;  aluminium, 
•jy.  This  alloy  is  used  for  making  cheap  imitation  gold  ware,  re¬ 
sembling  gold  in  color  and  not  tarnishing  in  the  air. 

Britannia  Metal  and  Similar  Alloys. — These  alloys  are  of  great 
importance.  They  are  readily  fusible  and  very  useful  for  cheap 
ware,  which  may  frequently  be  silvered.  Britannia  metal  consists 
principally  of  tin  alloyed  with  antimony.  Many  varieties  contain 
only  these  two  metals  and  may  be  considered  as  tin  hardened  by 
antimony.  Other  similar  alloys  contain,  however,  in  addition, 
certain  quantities  of  copper,  sometimes  lead,  and  occasionally 
bismuth. 

The  following  table  shows  the  composition  of  several  varieties  of 
Britannia  metal: 


Britannia  metal. 

Parts. 

Tin. 

Anti¬ 

mony. 

Copper 

Zinc. 

Lead. 

Bis¬ 

muth. 

English . 

81.9 

16.25 

1.84 

“  . 

90.62 

7.81 

1.46 

(( 

90.1 

6.3 

3  1 

0.5 

(< 

85-4 

9.66 

0.81 

3.06 

Pewter . 

81.2 

5-7 

1.6 

iiS 

(< 

89-3 

7.6 

1.8 

1.8 

“  . 

833 

6.6 

1.6 

3.06 

1.6 

Tutania . 

9r-4 

0.7 

0-3 

7.6 

Queen’s  metal . 

88.5 

7-i 

35 

0.9 

German . 

72 

24 

4 

“  . 

84 

9 

2 

5 

“  (cast) . 

20 

64 

10 

6 

Malleable  (cast) . 

48 

3 

48 

.... 

I 

Birmingham  (sheet) . 

90.6 

7.8 

i-5 

“  (cast) . 

90.71 

9.2 

0.09 

Karmarsch’s . 

8S 

5 

3-6 

1-4 

.... 

1.6 

Keller’s . 

85.7 

10.4 

I 

1.8 

Wagner’s  (fine) . 

85.64 

9.66 

0.81 

3.06 

0.83 

Ashberry  Metal. — Copper,  2  parts;  tin,  So;  antimony,  14; 


110 


THE  METAL  WORKER’S  HANDY-BOOK. 


zinc,  i  ;  nickel,  2;  aluminium,  i.  Or  copper,  3  parts;  tin,  79; 
antimony,  15  ;  zinc,  2  ;  nickel,  1.  Used  for  coffee-pots,  tea-pots 
and  all  similar  articles  generally  made  of  Britannia  metal. 

Biddery  Metal. — Genuine  East  India  Biddery  metal  consists  of 
copper,  3.5  parts;  zinc,  93.4;  lead,  3.1.  Or  copper,  11.4  parts; 
zinc,  84.3;  tin,  1.4;  lead,  2.9. 

Minofor  Metal. — Copper,  3.26  parts  ;  tin,  67.53  >  antimony,  17; 
zinc,  8.94.  Or  copper,  4  parts ;  tin,  66;  antimony,  20;  zinc,  9; 
iron,  1.  Used  for  the  same  purposes  as  Britannia  metal. 

Manganese  Alloys. — A  favorable  effect  is  produced  by  an  addi¬ 
tion  of  manganese  to  bronze,  brass,  copper,  etc.  All  varieties  of 
commercial  copper,  as  well  as  bronzes,  contain  more  or  less  oxide, 
which  injures  the  properties  of  these  alloys,  especially  decreasing 
their  tenacity  and  malleability.  The  removal  of  such  admixtures 
of  oxide  is  effected  by  substances  which  have  a  greater  affinity  for 
oxygen  than  copper,  for  instance,  by  an  addition  of  phosphorus  in 
the  preparation  of  phosphor-bronze.  Metallic  manganese  acts, 
however,  far  more  energetically,  as  it  does  not  volatilize  like  phos¬ 
phorus  at  the  fusing  temperature.  For  this  purpose  an  alloy  of 
copper  and  manganese,  the  so-called  cupro-manganese,  consisting 
of  copper,  70.5  parts;  manganese,  25,  and  coal,  0.5,  is  recom¬ 
mended.  Of  this  composition  an  addition  of  2^3  per  cent,  suffices 
for  most  cases.  The  process  is  very  simple.  After  melting  the 
bronze  masses  the  metal-bath  is  covered  with  pulverized  wood 
charcoal,  and  the  pieces  of  cupro-manganese  previously  weighed 
and  reduced  to  small  pieces  are  allowed  slowly  to  slide  into  the 
crucible.  Fusion  takes  place  instantaneously,  but  the  crucible  is 
for  a  few  moments  to  be  replaced  upon  the  fire  in  order  to  some¬ 
what  increase  the  temperature  reduced  by  the  addition  of  the  cold 
pieces  of  metal.  In  pouring  out  proceed  in  the  ordinary  manner. 
To  enclose  the  oxide  of  manganese  formed  by  this  process  add  to 
the  charcoal  with  which  the  metal-bath  is  covered  about  one-half 
its  quantity  of  pure  carbonate  of  soda  or  potash.  The  following 
alloys  are  prepared  according  to  this  method  : 

I.  Tin,  16  parts;  zinc,  3^  ;  lead,  3^  ;  cupro-manganese,  1. 

II.  Tin,  16  ;  zinc,  3  ;  lead,  3;  cupro-manganese,  2. 


ALLOYS  AND  AMALGAMS. 


Ill 


III.  Red  Brass. — Copper,  85  ;  tin,  14  ;  cupro-manganese,  1. 
Or  copper,  81  ;  tin,  17;  cupro-manganese,  2. 

IV.  Udiite  Metal. — Tin,  42  ;  lead,  40  ;  antimony,  20  ;  cupro- 
manganese,  2. 

Ferro-ma7iganese. — This  is  composed  of  manganese,  75  parts, 
and  iron,  75,  and  may  be  used  for  the  preparation  of  sterro-metal : 
copper,  54  parts ;  zinc,  40;  ferro-manganese,  6. 

A  composition  of  cupro-manganese,  consisting  of  copper,  70 
per  cent.,  and  manganese,  30  per  cent.,  is  used  as  an  addition  to 
many  alloys,  especially  for  tombac,  brass  and  bronze.  By  this  ad¬ 
dition  greater  density,  solidity  and  extensibility  are  imparted  to 
the  alloys.  A  copper-tin  alloy  with  6  per  cent,  manganese  possesses 
the  hardness  of  steel.  For  bearings  the  alloy  consists  of  copper,  80 
parts  ;  tin,  6  ;  zinc,  5  ;  cupro-manganese,  9.  For  rolls  an  alloy 
composed  of  tin,  64  parts;  copper,  8;  antimony,  16;  lead,  10; 
and  cupro-manganese,  2,  is  recommended.  For  malleable  brass, 
copper,  56^  parts;  zinc,  42;  and  cupro-manganese,  i)4. 

Manganese  alloys  are  capable  of  taking  a  good  polish  and  have 
a  white  to  rose-color  color.  Cupro-manganese  is  used  in  refining 
copper  for  the  reduction  of  cuprous  oxide,  the  manganese  alloy 
playing  in  this  case  a  role  corresponding  to  that  of  ferro-manganese 
in  the  preparation  of  steel. 

Manganese  Silver  consists  of  copper,  80  per  cent.  ;  manganese, 
15/  and  zinc,  5.  It  is  white,  takes  a  good  polish  and  is  readily 
worked. 

Manganese  Steel. — To  the  steel  melting  quietly  80  per  cent, 
ferro-manganese  is  added  in  such  quantity  as  desired.  The  steel 
is  then  poured  out.  To  obtain  steel  with  9  per  cent,  manganese 
o.  n  to  0.12  per  cent,  of  the  80  per  cent,  ferro-manganese,  to¬ 
gether  with  5.5  to  6  per  cent,  of  carbon,  have  to  be  added.  This 
steel  mixture  liquefies  with  ease.  The  pieces  prepared  from  it  are 
very  resistant  to  shocks.  It  is  difficult  to  work  with  drill  or  chisel, 
but  can  be  conveniently  hammered  and  stretched. 

Hadfield' s  Ma?iganese  Steel. — The  electrical  resistance  of  the 
non-magnetic  manganese  steel  is  8  times  greater  than  that  of  ordinary 
Steel  and  iron  and  30  times  greater  than  that  of  copper.  Material 


112 


THE  METAL  WORKER’S  HANDY-BOOK. 


with  5  or  6  per  cent,  of  manganese  is  very  hard;  with  io  per  cent., 
soft ;  with  22  per  cent.,  hard.  For  wrought  material  the  best  con¬ 
tent  is  14  per  cent.,  with  not  over  1  per  cent,  of  carbon.  In 
France  manganese  steel  is  used  for  horse-shoes,  whole  regiments 
of  cavalry  being  provided  with  them. 

Nickel  Alloys. — 1.  Nickel  and  Copper.  Nickel  and  copper  unite 
in  a  wide  range  of  proportions,  the  color  of  the  alloys  varying  from 
copper-red  to  the  blue-white  of  the  nickel.  The  use  of  alloys  of 
copper  and  nickel  alone  is  limited  ;  they  are  chiefly  employed  for 
coinage,  the  beautiful  white  color  and  considerable  hardness  im¬ 
parted  to  copper  by  an  addition  of  nickel  making  them  especially 
suitable  for  this  purpose. 

Nickel  Coins  of  the  United  States,  Belgium  and  Brazil. — Copper, 
75  parts  ;  nickel,  25. 

2.  Nickel,  Copper  and  Zinc  Alloys. — These  alloys  form  the  mix¬ 
tures  of  metals  known  as  German  silver,  packfong,  argent  neuf 
etc.  The  preparation  of  German  silver  must  be  executed  with  the 
greatest  care,  since  nickel  has  a  very  high  melting  point.  The 
more  readily  fusible  metals  are  first  melted  and  alloyed  together, 
after  which  the  fused  nickel  is  brought  into  the  crucible  and  the 
whole  vigorously  stirred  with  a  stout  wooden  stick. 

The  following  table  gives  the  composition  of  various  kinds  of  Ger- 
man  silver ; 


Copper 

Zinc. 

Parts. 

Nickel 

Lead. 

Iron. 

r 

So 

31-3 

18.7 

French  for  sheet . -( 

50 

30 

20 

l 

53-3 

25 

16.7 

f 

50 

25 

25 

Vienna . -1 

55-6 

22 

22 

( 

60 

20 

20 

Berlin . / 

54 

28 

18 

t 

55-5 

29.I 

i7-5 

f 

63-34 

17.01 

1913 

English . -{ 

62.40 

22.15 

15-05 

( 

62.43 

26.05 

10.85 

ALLOYS  AND  AMALGAMS. 


113 


Various  kinds  of  German  Silver 


Parts. 

Copper 

Zinc. 

Nickel 

Lead. 

Iron. 

English . 

57-40 

25 

13 

3 

26.3 

36.8 

36.8 

Chinese . ■ 

43-8 

40.6 

15  6 

45  7 

36  9 

17.9 

40.4 

25-4 

31.6 

2.60 

' 

48-5 

243 

24.3 

2.9 

54-5 

21.8 

21.8 

1.9 

For  casting . ■ 

58-3 

19.4 

19.4 

2-9 

57-8 

27.1 

14  3 

0.8 

57 

20.0 

20 

3 

Sheffield — 

Common  (yellow) . 

59-3 

25-9 

14.8 

Silver- white . 

55  2 

24.1 

20.7 

Electrum  (bluish) . 

51.6 

22.6 

25.8 

Hard  (can  be  worked  cold) . 

45-7 

20 

3I-3 

Fricke’s — 

Bluish-yellow  (hard) . 

55-5 

39 

5-5 

Pale  yellow  (ductile) . 

62.5 

31  2 

6-3 

Silvery  (hard) . 

50 

18.8 

31.2 

“  (harder) . 

59 

30 

IO 

Common  formula . 

55 

25 

20 

Many  varieties  of  German  silver  contain  different  quantities  of 
iron,  manganese,  tin  or  very  frequently  lead  to  change  the  proper¬ 
ties  of  the  alloy  or  to  cheapen  it.  An  addition  of  lead  makes 
German  silver  more  fusible ;  one  of  tin  acts  in  a  certain  sense  as 
in  bronze,  making  the  alloy  denser  and  more  sonorous  and  caus¬ 
ing  it  to  take  a  better  polish.  An  addition  of  iron  or  manganese 
increases  the  white  color  of  the  alloy,  but  also  renders  it  more  re¬ 
fractory  and  inclining  it  towards  brittleness. 

Alfenide,  Argiroide  and  Allied  Alloys. — The  alloys  brought  into 
commerce  under  these  and  many  other  names  consist  in  most  cases 
of  a  mixture  of  metals  closely  resembling  German  silver  ;  they  are, 
however,  generally  electro-plated  with  pure  silver. 

8 


114 


THE  METAL  WORKER’S  IIANDY-BOOK 


Albafa  Metal. — Nickel,  3  to  4  parts;  copper,  20;  zinc,  16. 
Used  for  plated  goods. 

Alfenide. — Copper,  59.6  parts;  zinc,  30.3;  nickel,  10. 1  ;  and  a 
trace  of  iron. 

British  Plate  Metal. — Copper,  20  parts;  nickel,  5  to  6  ;  zinc, 
8  to  10.  Used  for  plated  goods. 

Metal  for  Spoons, -Forks,  etc. — Copper,  69.8  parts;  nickel,  19.8; 
zinc,  5.5  ;  cadmium,  4.7. 

White  Alloy  Resisting  the  Action  of  Vegetable  Acids. — Tin,  875 
parts;  nickel,  55  ;  antimony,  50;  bismuth,  20. 

White  Argentan. — Copper,  8  parts  ;  nickel,  3  ;  zinc,  35.  This 
beautiful  composition  is  a  deceptive  imitation  of  silver. 

3.  Alloys  of  Nickel  and  Steel. — The  composition  of  the  alloy  can 
be  as  effectually  controlled  in  the  open  hearth  furnace  as  in  the  cru¬ 
cible.  It  can  be  made  in  any  good  open  hearth  furnace  working 
at  a  fairly  good  heat.  If  the  charge  be  properly  worked,  nearly 
all  the  nickel  will  be  found  in  the  steel ;  almost  nothing  being  lost 
in  the  slag.  The  ingots  are  clean  and  smooth  in  appearance  on  the 
outside,  but  those  richest  in  nickel  are  a  little  more  “  piped  ”  than 
ingots  of  ordinary  mild  steel.  Any  scrap  produced  can  be  re¬ 
melted  in  making  another  charge  without  loss  of  nickel.  No  ex¬ 
traordinary  care  is  required  when  reheating  the  ingots  for  hammer¬ 
ing  or  rolling.  If  the  steel  has  been  properly  made  and  be  of 
correct  composition  it  will  hammer  and  roll  well  whether  it  con¬ 
tains  little  or  much  nickel.  Tests  of  steel  with  varying  contents 
of  nickel  showed  that  the  addition  of  4  per  cent,  of  nickel  raises 
the  elastic  limit  from  16  up  to  28  tons,  and  the  breaking  strain 
from  30  up  to  40.6  tons  without  impairing  the  elongation  or  con¬ 
traction  of  area  to  any  noticeable  extent.  In  another  case  some¬ 
what  similar  results  were  found  with  an  addition  of  only  3  per 
cent,  of  nickel,  combined  with  an  increase  of  the  carbon  to  0.35 
per  cent.  In  two  cases,  one  containing  2.0  per  cent,  of  nickel, 
0.90  per  cent,  of  carbon  and  0.50  per  cent,  of  manganese,  the 
other  4  per  cent,  of  nickel,  0.85  of  carbon  and  0.50  of  manganese, 
there  was  an  extreme  hardness  due  in  part  to  the  large  quantity  of 
carbon  present,  but  also  to  the  presence  of  nickel  in  addition. 


ALLOYS  AND  AMALGAMS. 


115 


The  quality  of  hardness  obtains  as  the  nickel  is  increased  until 
about  20  per  cent,  is  reached,  when  a  change  takes  place,  and  suc¬ 
cessive  additions  of  nickel  tend  to  make  the  steel  softer  and  more 
ductile,  and  even  to  neutralize  the  influence  of  carbon.  In  the 
25  per  cent,  nickel  steel  there  are  some  peculiar  and  remarkable 
properties.  In  the  unannealed  specimen  the  breaking  strain  is 
high  and  the  elastic  limits  moderately  so,  but  in  the  annealed  piece, 
while  the  breaking  strain  remains  good,  the  elastic  limit  is  very 
greatly  reduced,  down  to  one-third  of  the  breaking  strain.  Again, 
in  both  cases,  the  ductility  as  shown  by  the  extension  before 
fracture  is  marvellous,  reaching  40  per  cent,  in  8  inches.  Another 
feature  is  that  this  elongation  is  nearly  uniform  throughout  the 
piece.  The  whole  of  the  series  of  nickel  steels  up  to  50  per  cent, 
nickel  take  a  good  polish  and  finish,  with  a  good  surface,  the  color 
being  lighter  with  the  increased  additions  of  nickel.  The  steels 
rich  in  nickel  are  practically  non-corrodible,  and  those  poor  in 
nickel  are  much  better  than  other  steels  in  this  respect.  The  1  per 
cent,  nickel  steel  welds  fairly  well,  but  this  quality  deteriorates 
with  each  addition  of  nickel.  The  25  per  cent,  nickel  steel,  with 
its  peculiar  properties  of  high  breaking  strain,  great  ductility  and 
comparatively  low  elastic  limit,  is  extremely  well  adapted  for  all 
operations  involving  considerable  deformation  ;  for  instance,  for  deep 
stamping  and  flanging,  whilst  its  non-corrodibility  will  render  it 
invaluable  for  a  great  number  of  purposes.  In  the  region  between 
25  per  cent,  and  about  5  per  cent,  of  nickel  are  an  abundance  of 
possibilities  as  yet  comparatively  unknown,  in  which  will  no  doubt 
be  found  materials  for  tool  steel  equal,  if  not  superior,  to  anything 
at  present  known. 

Type  Metal. — -An  alloy  of  lead  and  antimony  answers  best  for 
this  purpose.  At  present  a  great  many  receipts  for  type  metal  are 
known,  in  the  preparation  of  which  other  metals  besides  lead  and 
antimony  are  used  for  the  purpose  of  rendering  the  alloy  more 
fusible. 

In  the  following  table  some  alloys  suitable  for  casting  type  are 
given  : 


116 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


Ehrhardt' s  Type  Metal  is  composed  of  zinc,  89  parts;  tin,  4; 
lead,  3  ;  copper,  4;  or,  zinc,  93  ;  tin,  3;  lead,  3;  copper,  2. 

Music  Plates. — I.  Tin,  5  to  7.5  parts;  antimony,  5  to  2.5.  II. 
Lead,  16;  antimony,  1.  III.  Lead,  8;  antimony,  2;  tin,  1.5. 
IV.  Lead,  4;  antimony,  2;  zinc,  1.  V.  Lead,  7.5;  antimony, 
2.5  ;  copper,  0.5. 

Various  Alloys. — Acid-proof  Bronze.  This  alloy  may  be  advan¬ 
tageously  substituted  for  hard  rubber,  porcelain  and  other  sub¬ 
stances  which,  though  acid-proof,  are  much  exposed  to  wear  and 
tear,  and  sometimes  too  costly.  The  alloy  consists  of  copper,  15 
parts;  tin,  2.34;  lead,  1.82;  antimony,  1.  The  metals  are 
melted  together  in  the  usual  manner,  and  the  alloy  is  worked  like 
ordinary  bronze. 

Alloy  for  Casting  Small  Articles. — Fuse  a  mixture  of  79  per 
cent,  of  cast-iron,  19.50  of  tin  and  1.50  of  lead.  This  alloy  has 
a  beautiful  appearance,  and  fills  the  mould  completely.  It  is 
to  a  certain  extent  malleable. 

Alloy  for  Moulds  for  Pressed  Glass. — An  alloy  suitable  for  this 
purpose  is  obtained  by  melting  together  100  parts  of  iron  with  10 
to  25  of  nickel. 

Alloy  of  Copper  and  Antimony. — A  beautiful  alloy  is  produced 
by  fusing  together  in  a  crucible  at  a  strong  heat  equal  parts  of 
antimony  and  copper.  The  compound  is  hard  and  of  a  beautiful 
violet  hue.  This  alloy  has  not  yet  been  applied  to  any  useful 


ALLOYS  AND  AMALGAMS. 


117 


purpose,  but  its  excellent  qualities,  independent  of  its  color,  en¬ 
title  it  to  consideration. 

Alloys  for  Calico-printing  Rollers. — Hauvel  considers  a  semi- 
hard  bronze  of  the  following  composition  the  best  material  for  the 
rollers:  Copper,  86  parts;  tin,  14;  zinc,  2.  Rendel,  on  the 
other  hand,  found  an  English  roller  material  composed  of  copper, 
5.6  parts;  zinc,  78.3  ;  tin,  15.8.  Though  this  compound  gives  a 
hard,  fine-grained  alloy,  it  is  likely  to  be  readily  attacked  by  the 
colors  used  in  printing. 

According  to  analyses  by  J.  D6pierreand  P.  Spiral,  the  compo¬ 
sition  of  the  scrapers  (sometimes  called  doctors  or  ductors)  in¬ 
tended  to  remove  the  surplus  of  colors  from  the  rollers  is  as 
follows  : 


Copper. 

Zinc. 

Tin. 

Yellow  French  scrapers . 

.  78-75 

12.50 

8-75 

“  English  “  . 

.  80.50 

10.50 

8.00 

“  German  “  . 

9.80 

4.90 

Alloys  for  Small  Patterns  in  Foundries. — I.  Tin,  7.5  parts  ;  lead, 
2.5.  II.  Zinc,  75  parts;  tin,  25.  III.  Tin,  30  parts;  lead,  70. 
The  last  of  these  alloys  is  for  patterns  which  will  not  be  in  frequent 
use,  and  which  may  be  mended,  bent,  etc.  The  first  gives  harder 
and  stiffer  patterns;  the  second  is  harder  than  tin  and  more  tena¬ 
cious  than  zinc,  while  at  the  same  time  it  preserves  a  certain 
ductility. 

Bimningham  Platinum. — This  is  a  white  alloy  for  buttons,  and 
consists  of  copper,  43  per  cent.  ;  zinc,  57.  Other  alloys  for  white 
buttons  are:  I.  Yellow  brass,  32  parts;  zinc,  3;  tin,  1.  II.  Yellow 
brass,  32  parts;  zinc,  4;  tin,  2. 

Calin. — By  this  name  is  known  an  alloy  used  by  the  Chinese  for 
lining  tea-chests.  It  is  composed  of  lead,  126  parts;  tin,  17.5; 
copper,  1.25,  and  a  trace  of  zinc. 

Cooper's  Alloy  for  Steel-pens. — Copper,  1  part;  platinum,  4; 
silver,  8.  It  is  distinguished  by  its  hardness,  elasticity  and  incor¬ 
rodibility. 

Dysiot. — By  this  name  is  known  a  bearing-metal  manufactured 


118 


TITE  METAL  WORKER’S  IIANDY-BOOK. 


by  Rompel  &  Co.,  of  Homburg.  It  is  prepared  by  melting 
together  copper,  62  parts;  lead,  18;  tin,  10;  and  zinc,  10. 

Fahlun  or  Tin  Brilliants. — An  alloy  of  especially  fine  lustre  is 
known  under  the  name  of  “Fahlun  brilliants.”  It  is  used  for 
stage  jewelry  and  consists  of  tin,  3  parts,  and  lead,  2,  or  of  tin,  3 
parts,  and  lead,  1.  For  the  production  of  brilliants  melt  small 
portions  of  the  alloy  in  an  iron  crucible.  By  dipping  into  the 
fluid  mass,  previously  freed  from  every  particle  of  oxide,  pieces  of 
glass  or  brass,  ground  like  brilliants  and  highly  polished,  a  thin 
layer  of  metal  adheres  to  them  which,  after  cooling,  can  be  readily 
detached.  The  separate  pieces  may  be  connected  by  soldering. 
Sometimes  the  alloy  is  poured  into  moulds  faceted  in  the  same 
manner  as  diamonds. 

Gold  and  Palladium  Alloys. — Alloys  of  gold,  copper,  silver  and 
palladium  have  a  brownish-red  color,  and  the  hardness  of  iron. 
They  are  sometimes  used  for  bearings  of  the  arbors  in  fine  watches, 
as  they  cause  but  little  friction  (less  than  the  jewels  used  for  the 
same  purpose)  and  never  rust  on  exposure  to  the  air.  The  compo¬ 
sition  used  in  the  Swiss  and  English  watch  factories  consists  of 
gold,  18  parts;  copper,  13;  silver,  11  ;  palladium,  6. 

Gold-like  Alloy. — This  alloy  closely  resembling  gold  is  obtained 
by  melting  together  copper,  16  parts;  zinc,  1  ;  and  platinum,  7. 
The  copper  and  platinum  are  first  covered  with  borax,  next  with 
pulverized  charcoal,  and  melted,  after  which  the  zinc  is  added. 
The  alloy  produced  is  easily  worked  and  may  be  drawn  into  the 
finest  wire;  it  does  not  turn  blue. 

Iron  Alloy. — A  compact,  very  malleable  iron  alloy  capable  of 
taking  a  high  polish  has  been  patented  in  England,  by  W.  M. 
Arnold.  It  is  obtained  by  melting  together  pig-iron,  50  lbs.  ; 
sodium,  y2  lb.  ;  copper  and  antimony,  each  y  lb.,  and  zinc  2 y2 
lbs.  It  is  claimed  to  be  especially  suitable  for  ships’  screws,  it  re¬ 
sisting  quite  well  the  corroding  action  of  sea-water.  By  omitting 
the  sodium  and  decreasing  the  quantity  of  zinc  a  softer  variety  of 
iron  is  obtained,  while  the  additions  of  larger  quantities  of  sodium 
and  zinc  and  the  decrease  of  the  content  of  copper  yield  a  harder 
material. 


ALLOYS  AND  AMALGAMS. 


119 


Lemarquand' s  Non-oxidizable  Alloy. — Copper,  750  parts;  nickel, 
140;  black  oxide  of  cobalt,  20;  tin  in  sticks,  18;  zinc,  72.  The 
metals  must  be  pure. 

Lutecine  or  Paris  Metal. — Copper,  800  parts;  nickel,  160;  tin, 
20;  cobalt,  10  ;  iron,  5  ;  and  zinc,  5. 

Malleable  Brass. — Alloy,  copper,  33  parts,  and  zinc,  25  parts, 
the  copper  being  loosely  covered  with  the  zinc  in  the  crucible. 
As  soon  as  the  copper  is  melted  pure  zinc  is  added.  The  alloy  is 
then  cast  in  molding  sand  into  the  shape  of  bars,  which,  it  is  said, 
are  malleable  into  any  form  when  still  hot.  To  make  brass  soft, 
heat  it  to  a  low  red  and  plunge  in  water.  It  cannot  be  hardened 
except  by  rolling  and  hammering. 

Marley’s  Non-oxidizable  Alloy. — Iron,  10  parts;  nickel,  35; 
brass,  25  ;  tin,  20  ;  zinc,  xo.  Articles  prepared  from  this  alloy 
are  heated  to  a  white  heat  and  dipped  into  a  mixture  of  sul¬ 
phuric  acid,  60  parts;  nitric  acid,  10  ;  hydrochloric  acid,  5  ;  and 
water,  25. 

New  Alloys. — I.  An  alloy  which  is  said  to  practically  resist  the 
attack  of  most  acid  and  alkaline  solutions  is  composed  as  follows : 
Copper,  15  parts;  tin,  2.34;  lead,  1.82;  antimony,  1.  This 
alloy  is,  therefore,  a  bronze  with  the  addition  of  lead  and  anti¬ 
mony.  It  is  claimed  that  it  can  be  very  advantageously  used  in 
the  laboratory  to  replace  vessels  or  fittings  of  ebonite,  vulcanite  or 
porcelain. 

II.  Pure  copper  or  tin  is  melted  and  to  the  melted  mass  is  added 
a  piece  of  arsenic  enclosed  in  a  copper  capsule.  After  thorough 
stirring  the  mass  is  granulated  by  pouring  into  water.  The 
granules  of  the  alloy  thus  obtained  are  remclted  and  then  used  as 
an  addition  for  the  preparation  of  bronze  and  other  alloys,  whereby 
it  is  claimed  the  alloy  acquires  greater  elasticity,  strength  and 
homogeneity  than  phosphor-bronze  and  similar  alloys. 

III.  For  the  Manufacture  of  Jewelry,  etc. — This  alloy  has  a 
color  resembling  that  of  the  various  alloys  of  gold.  It  is  very  re¬ 
sistible  and  ductile  and  acquires  great  lustre  by  polishing.  It 
consists  of  978  parts  by  weight  of  pure  copper ;  2  of  gold  ;  and  20 
of  aluminium.  The  copper  and  gold  are  first  melted  in  a  crucible 


120 


TITE  METAL  WORKER’S  ITANRY-BOOK. 


of  chamotte  *  or  other  refractory  material,  and  when  the  metals  are 
fluid  the  aluminium  is  added.  When  not  more  than  2  lbs.  of  the 
alloy  are  made  at  one  time  the  mass  is  kept  in  a  fused  state  for 
half  an  hour,  about  ozs.  of  borax  being  added  as  a  flux.  The 
melted  mass  is  then  poured  into  ingots.  The  alloy  thus  obtained  can 
be  worked  into  sheet,  wire  or  ribbon,  as  required  for  the  manu¬ 
facture  of  jewelry.  To  obtain  the  various  colors  it  is  only  neces¬ 
sary  to  vary  the  proportions  of  the  three  metals;  for  red,  for  in¬ 
stance,  somewhat  less  gold  and  aluminium  is  used,  for  yellow 
somewhat  less  gold,  and  for  green  somewhat  less  gold  and  more 
aluminium. 

New  Imitations  of  Gold  and  Silver. — To  prepare  an  alloy  having 
the  appearance  and  color  of  gold,  melt  in  a  crucible  800  parts  by 
weight  of  pure  copper,  25  of  platinum,  and  10  of  tungstate  of  lime, 
and  granulate  the  melt  by  letting  it  run  into  water  containing  for 
every  35.31  cubic  feet  17  ozs.  each  of  slaked  lime  and  potash. 
The  purpose  of  these  ingredients  is  to  purify  the  alloy.  The 
metallic  granules  are  then  collected  and  dried,  and  after  remelting 
them  in  the  crucible,  170  parts  by  weight  of  gold  are  added.  This 
alloy,  when  cast  into  ingots,  has  the  appearance  of  red  gold.  Differ¬ 
ent  colors  may  be  obtained  by  varying  the  proportions  of  the 
metals.  Boric  acid,  saltpetre,  and  sodium  chloride,  previously 
fused  together  in  equal  proportions,  are  used  as  flux;  the  proportion 
is  7  drachms  to  1  lb.  of  alloy. 

The  alloy  used  for  the  imitation  of  silver  consists  of  iron,  65 
parts;  nickel,  23  ;  tungstate  of  lime,  4;  aluminium,  5  ;  and  copper, 
5.  The  iron  and  tungstate  of  lime  are  fused  together,  and  granu¬ 
lated  in  the  same  manner  as  above  described,  with  the  exception 
that  the  water  into  which  the  alloy  is  allowed  to  run  contains  2  lbs. 
each  of  slaked  lime  and  potash  to  every  35.31  cubic  feet.  During 
fusion  in  the  crucible  the  metals  must  be  carefully  covered  with  a 
flux  consisting  of  1  part  of  boric  acid  and  1  of  potassium  nitrate. 
In  the  crucible  containing  the  aluminium  and  the  copper  place  a 
piece  of  soda  (15  grains  to  every  10  lbs.  of  metal),  to  prevent  the 


*  A  mixture  of  unburnt  fire-clay  anti  dust  of  fire-bricks,  glass  pots  or  seggars. 


ALLOYS  AND  AMALGAMS. 


121 


oxidation  of  the  aluminium ;  add  also  some  charcoal,  to  prevent 
the  oxidation  of  the  copper.  Before  granulating  the  metal,  thor¬ 
oughly  stir  the  contents  of  each  crucible  with  a  ladle  of  fire¬ 
clay.  The  granulated  metal  is  dried,  then  melted  together  in  the 
above-mentioned  proportions,  thoroughly  stirred,  and  cast  into 
ingots.  This  alloy  has  the  appearance  of  silver  or  of  platinum. 
The  alloys  resist  the  action  of  sulphuretted  hydrogen,  and  are  not 
attacked  by  vegetable  acids  and  but  slightly  by  mineral  acids ;  they 
are  ductile  and  flexible. 

New  Method  of  preparing  Alloys. — The  alloys  consist  of  heavy 
metals  and  the  sulphides  of  the  alkali  metals,  or  metals  of  the  alka¬ 
line  earths.  Preferably  sulphide  of  strontium  is  alloyed  with 
copper,  in  order  to  obtain  a  product  of  a  constant  gold-like  color. 
For  this  purpose  zinc  is  melted  together  with  8  to  15  per  cent,  of 
calcined  strontium  sulphate,  and  the  resulting  alloy  allowed  to 
cool.  To  this  alloy  a  varying  quantity  of  copper  is  added,  accord¬ 
ing  to  the  color  and  power  of  resistance  required.  As  much  of  the 
zinc  as  desired  may  be  expelled  by  subsequent  cupellation. 

Non-Magnetic  Alloys  for  Watches. — To  overcome  the  injurious 
effect  of  magnetic  action  upon  watches,  alloys  of  palladium  are 
proposed  as  substitutes  for  steel  wherever  it  is  employed  in  the 
works.  The  composition  of  the  new  alloys  varies  from  45  to  75 
parts  of  palladium,  15  to  30  parts  of  copper,  20  to  25  parts  of 
silver,  with  sometimes  the  addition  of  small  proportions  of  iron, 
steel,  nickel,  gold,  and  platinum.  These  alloys  are  claimed  to  be 
unoxidizable  in  moist  air,  to  preserve  their  elasticity  indefinitely, 
not  to  vary  sensibly  with  changes  of  temperature,  and  remain 
uninfluenced  by  proximity  to  dynamos. 

Another  non-magnetic  alloy,  recently  brought  out  by  Messrs. 
Ostermann  and  Lacroix,  of  Geneva,  Switzerland,  is  made  of  from 
30  to  40  parts  of  gold,  30  to  40  parts  of  palladium,  o.  1  to  5  parts 
of  rhodium,  10  to  20  parts  of  copper,  o.  1  to  5  parts  of  manganese, 
and  the  same  proportion  of  silver  and  platinum.  The  copper  and 
manganese  are  first  mixed,  after  which  the  other  articles  are  added; 
or  all  the  metals  may  be  put  into  a  crucible  at  the  same  time,  the 
manganese  being  used  for  the  bottom  layer. 


THE  METAL  WORKER’S  HANDY-BOOK. 


12‘J 

Non- Oxidizable  Alloy. — Iron,  io  parts;  nickel,  36;  copper,  tin, 
zinc,  each,  18.  This  metal  has  a  white  color,  with  a  slightly  red¬ 
dish  tinge. 

Platinoid. — This  alloy  is  a  kind  of  German  silver,  with  an  addi¬ 
tion  of  1  to  2  per  cent,  of  tungsten.  The  latter,  in  the  form  of 
phosphor-tungsten,  is  first  melted  together  with  a  certain  quantity 
of  copper,  the  nickel  is  next  added,  then  the  zinc,  and  finally  the 
remainder  of  copper.  In  order  to  remove  the  phosphorus  and  a 
portion  of  the  tungsten,  both  of  which  separate  dross,  the  resulting 
compound  is  several  times  remelted.  Finally  an  alloy  of  a  beautiful 
white  color  is  obtained,  which,  when  polished,  closely  resembles 
silver,  and  retains  its  lustre  for  a  long  time.  Platinoid  has  the 
properties  of  German  silver  in  a  pre-eminent  degree.  It  shows 
great  resistance,  which  remains  quite  constant  at  different  tempera¬ 
tures,  and  is  about  1  J4  times  greater  than  that  of  German  silver. 

Platinum  Bronze. — This  name  is  applied  to  an  alloy  prepared 
from  100  parts  of  pure  nickel,  10  of  tin,  and  1  of  platinum,  by 
adding  to  the  melted  nickel  the  platinum  and  4  parts  of  the  tin, 
and  then  gradually  the  remaining  6  parts  of  tin.  This  alloy  is 
intended  for  household  utensils.  For  bells,  etc.,  100  parts  of 
nickel,  20  of  tin,  2  of  silver,  and  1  of  platinum  are  used. 

Shakdo. — This  is  a  Japanese  alloy,  consisting  of  copper  and  gold, 
the  proportion  of  the  latter  varying  from  1  to  10  per  cent.  Articles 
made  from  this  composition  are,  after  polishing,  boiled  in  a  pickle, 
consisting  of  cupric  sulphate,  alum,  and  verdigris,  whereby  they 
acquire  a  bluish-black  color.  Shakdo  is  worked  into  scabbards, 
buckles,  etc.,  and  into  many  decorative  articles. 

Sideraphtiie. — This  alloy  consists  of  iron,  65  parts;  nickel,  23; 
tungsten,  4;  aluminium,  5  ;  and  copper,  5.  It  is  claimed  to  resist 
the  action  of  vegetable  acids,  and  to  be  quite  indifferent  towards 
mineral  acids. 

Soft  Alloy  for  Coating  Metals,  etc. — From  a  solution  of  cupric 
sulphate  precipitate  the  copper  with  zinc;  pulverize  the  precipitate, 
and  in  a  porcelain  dish  make  the  copper-dust  thus  obtained  into  a 
cake  with  pure  sulphuric  acid  of  1.85  specific  gravity.  According 
to  the  hardness  desired,  carefully  mix  20,  30,  or  36  parts  of  this 


ALLOYS  AND  AMALGAMS. 


123 


cake  with  70  parts  of  mercury,  and  wash  the  amalgam  thus  obtained 
with  an  abundance  of  warm  water  to  remove  all  traces  of  acid.  In 
10  to  12  hours  the  alloy  is  so  hard  that  it  will  scratch  tin.  For 
use  heat  the  alloy  until  it  can  be  worked  like  wax.  In  this  state 
it  is  applied  to  the  surface  of  the  article,  to  which,  after  cooling, 
it  adheres  with  great  tenacity. 

II.  Amalgams. — The  readiness  with  which  mercury  unites  with 
most  of  the  other  metals  to  form  definite  chemical  compounds, 
called  “amalgams,”  is  one  of  its  most  striking  properties  and  is 
turned  to  account  for  the  extraction  of  silver  and  gold  from  their 
ores.  Amalgams  are  crystalline  combinations  and  form  at  a  low 
temperature.  They  are  at  first  so  soft  that  they  can  be  kneaded 
like  wax,  but  after  some  time  harden  completely.  The  following 
are  some  of  the  most  important : 

Amalgam  of  Lipowitz' s  Metal. — This  amalgam  is  prepared  as 
follows:  Melt  in  a  dish,  cadmium,  3  parts;  tin,  4;  bismuth,  15, 
and  lead,  8,  and  add  to  the  melted  alloy  2  parts  of  mercury  pre¬ 
viously  heated  to  about  2120  F.  Amalgamation  takes  place  readily 
and  smoothly.  After  the  introduction  of  the  mercury  imme¬ 
diately  take  the  dish  from  the  fire  and  stir  the  liquid  mass  until  it 
solidifies.  While  Lipowitz’s  alloy  becomes  soft  at  140°  F.  and 
melts  at  158°  F.,  the  amalgam  melts  at  about  143. 50  F.  This 
amalgam  may  be  used  for  the  manufacture  of  small,  hollow  stat¬ 
uettes  and  busts,  which  can  be  readily  gilded  or  bronzed  by  the 
galvanic  process. 

Small  statuettes  are  readily  made  by  preparing  a  hollow  mould 
of  plaster  of  Paris  and  after  uniformly  heating  it  to  about  140° 
F.  pouring  in  the  melted  amalgam.  The  mould  is  then  swung  to 
and  fro,  this  being  continued  until  the  amalgam  is  solidified. 
After  cooling  the  mould  is  taken  apart  and  the  seams  trimmed  with 
a  sharp  knife.  The  operation  may  also  be  modified  by  placing  the 
mould  upon  a  rapidly  revolving  disk  and  pouring  in  the  melted 
amalgam  in  a  thin  stream.  By  the  centrifugal  force  developed  the 
melted  metal  is  hurled  against  the  sides  of  the  mould,  and  in  this 
manner  statuettes  of  considerable  size  can  be  cast. 

Copper  Amalgam. — Place  strips  of  zinc  in  a  solution  of  sulphate 


124 


TIIE  METAL  WORKER’S  IIANDY-BOOK. 


of  copper  and  shake  vigorously.  The  copper  thus  obtained  in  the 
form  of  a  delicate  powder  is  washed  and  while  still  moist  treated  in 
a  dish  with  a  solution  of  mercurous  nitrate.  Hot  water  is  then 
poured  over  the  copper,  the  dish  kept  warm,  and  the  mercury 
added.  The  contents  of  the  dish  are  then  kneaded  with  a  pestle 
until  the  pulverulent  copper  combines  with  the  mercury  to  a  plastic 
mass.  The  longer  the  kneading  is  continued  the  more  homo¬ 
geneous  the  mass  will  be.  The  best  proportions  to  use  are  3  parts 
of  copper  and  7  of  mercury. 

An  important  application  of  copper  amalgam  is  for  cementing 
metal,  it  being  only  necessary  to  apply  it  to  the  metals  to  be 
cemented,  which  must  be  bright  and  previously  heated  to  from 
176°  to  1940  F.,  and  press  them  togetner ;  they  will  be  joined  as 
firmly  as  if  soldered. 

A  composition  of  25  parts  of  copper  in  fine  powder  obtained  by 
precipitation  from  solutions  of  the  oxide  by  hydrogen,  or  the  sul¬ 
phate  of  zinc,  washed  with  sulphuric  acid  and  amalgamated  with  7 
parts  of  mercury,  after  being  well  washed  and  dried,  is  moderately 
hard,  takes  a  good  polish  and  makes  a  fine  solder  for  low  tempera¬ 
tures.  It  will  adhere  to  glass. 

An  imitation  of  gold,  which,  on  account  of  its  golden-yellow  color 
and  capability  for  taking  a  fine  polish,  is  suitable  for  the  manufac¬ 
ture  of  cheap  jewelry,  consists  of  copper,  86.4  parts;  mercury, 

i3-6- 

Gold  Amalgam. — This  is  formed  when  mercury  is  heated  with 
powdered  gold  or  gold-foil.  It  consists  usually  of  2  parts  of  gold 
to  1  of  mercury.  An  amalgam  suitable  for  fire-gilding  is  best  pre¬ 
pared  as  follows:  Heat  in  a  graphite  crucible,  rubbed  inside  with 
chalk  to  prevent  adhesion,  the  gold  to  be  alloyed  to  a  red  heat.  It 
is  not  absolutely  necessary  to  use  chemically  pure  gold,  but  it 
should  be  at  least  22  carat  fine  and  preferably  alloyed  with  silver 
instead  of  copper.  Gold  amalgam  containing  copper  becomes 
stone-hard  in  a  short  time,  and  a  small  content  of  it  impairs  its 
uniform  application  to  the  metals  to  be  gilded.  It  is  best  to  use 
the  gold  in  the  form  of  thin  sheets,  which  are  cut  into  small  pieces 
by  means  of  scissors,  and  brought  into  the  crucible.  When  the 


alloys  and  amalgams. 


125 


gold  is  heated  to  a  red  heat  introduce  about  the  eighth  or  ninth  part 
of  the  weight  of  the  gold  of  mercury  previously  heated  to  boiling. 
Stir  constantly  with  an  iron  rod,  and  after  a  few  minutes  remove 
the  crucible  from  the  fire.  If  the  finished  amalgam  were  allowed 
to  cool  in  the  crucible  it  would  become  strongly  crystalline  and  be 
unsuitable  for  fine  gilding.  To  prevent  this  it  is  at  once  poured 
into  a  larger  vessel  cooled  by  water.  By  keeping  this  amalgam  for 
some  time  crystallization  nevertheless  takes  place,  the  amalgam 
separating  from  the  mercury  in  excess,  and  it  is,  therefore,  advis¬ 
able  to  prepare  it  fresh  a  short  time  before  use.  Crystalline  amal¬ 
gam  can  be  restored  by  heating  in  a  crucible  with  an  excess  of 
mercury. 

Iron  Amalgam  is  only  used  in  the  industries  in  rare  cases  where 
iron  is  to  be  fire-gilt,  and  then  it  is  produced  upon  the  article  to 
be  gilded  itself.  For  this  purpose  the  article  previously  made 
bright  by  pickling  is  boiled  in  a  mixture  of  mercury,  12  parts; 
zinc,  1;  copperas,  2;  water,  12;  hydrochloric  acid,  1.  The 
mercury  dissolved  in  the>solution  separates  upon  the  iron  article,  a 
thin,  lustrous  layer  of  iron  amalgam  being  formed  upon  the  sur¬ 
face  to  which  the  amalgam  of  gold  can  be  readily  and  uniformly 
applied  without  further  preparation. 

Silver  Amalgam. — This  is  best  prepared  by  the  use  of  pulveru¬ 
lent  silver  obtained  by  the  reduction  of  silver  solution.  It  may  be 
prepared  by  bringing  a  solution  of  nitrate  of  silver  in  10  to  15 
parts  of  water  into  a  bottle,  adding  a  few  small  pieces  of  sheet  zinc 
and  vigorously  shaking  for  a  few  minutes.  The  silver  separating 
in  the  form  of  a  very  fine  black-gray  powder  need  only  be  washed 
and  dried  to  be  suitable  for  the  preparation  of  amalgam.  This 
finely  divided  powder  may  be  directly  dissolved  in  the  mercury, 
though  it  requires  some  time.  The  object  is  more  quickly  attained 
by  heating  the  mercury  nearly  to  boiling  in  a  crucible,  then  throw¬ 
ing  in  the  pulverulent  silver  and  quickly  combining  the  mass  by 
vigorous  stirring  with  an  iron  rod. 

Tin  Amalgam. — Tin  and  mercury  combine  readily  at  ordinary 
temperatures.  If  3  parts  of  mercury  are  brought  into  contact  with 
1  of  tin,  6-sided  crystals  of  tin  amalgam  are  formed.  Tin  amalgam 


126 


TIIE  METAL  WORKER’S  II ANDY-BOOK. 


is  used  for  silvering  looking-glasses.  When  pulverized  and  rubbed 
on  the  polishing-stone  it  forms  a  kind  of  mosaic  silver.  Electric 
amalgam  may  be  made  by  melting  tin  and  zinc  together  in  various 
proportions  in  a  porcelain  crucible.  The  mixture  is  well  stirred 
up  and  when  on  the  point  of  solidifying  the  mercury  is  added  and 
worked  into  the  mass.  The  whole  is  next  transferred  to  a  mortar 
warm  enough  to  keep  the  amalgam  soft,  while  it  is  well  worked  to¬ 
gether,  after  which  a  piece  of  tallow  or  lard,  not  quite  the  equal 
in  bulk  to  the  mass,  is  kneaded  in  until  the  amalgam  attains  the 
proper  consistency. 

Zinc  Amalgam  is  formed  by  mixing  and  triturating  zinc  filings 
with  mercury  at  a  heat  somewhat  below  the  boiling  point  of  the 
latter.  It  is  usually  prepared  by  pouring  mercury  into  zinc  at  the 
temperature  at  which  the  latter  is  just  kept  in  a  fused  state.  Care 
must  be  taken  to  keep  the  liquid  stirred  and  to  add  the  mercury 
slowly  and  in  as  fine  a  stream  as  possible. 


V. 

ANNEALING,  HARDENING,  TEMPERING. 

Annealing  of  Hard  and  Other  Iron  Castings. — The  process  con¬ 
sists  in  the  sudden  immersion  of  the  casting  at  a  certain  tempera¬ 
ture  into  a  fluid  in  order  to  make  it  capable  of  being  punched, 
drilled,  etc.,  like  wrought-iron.  The  principal  point  in  the  opera¬ 
tion  is  the  temperature  at  which  the  iron  is  immersed  in  the  fluid, 
the  proper  degree  being  the  moment  when  the  iron  is  reduced  to  a 
slight  red  heat,  i.  e.,  as  soon  as  the  red  heat  is  at  the  point  of 
disappearing.  The  fluid  in  which  the  iron  is  immersed  may  be 
composed  of  various  constituents,  provided,  however,  that  it  con¬ 
tains  no  acids  or  other  substances  injurious  to  the  iron.  The  best 
results  are  obtained  with  a  solution  of  treacle  and  water  of  specific 
gravity  1.005.  If  the  iron  shows  the  proper  degree  of  heat  when 
taken  from  the  chill  it  is  directly  brought  into  the  fluid,  otherwise 


ANNEALING,  HARDENING,  TEMPERING. 


127 


it  is  again  heated  somewhat  above  the  required  degree  and,  after 
cooling  to  a  slight  red  heat,  immersed  in  the  fluid. 

To  make  Steel  so  Soft  that  it  can  be  Worked  like  Copper. . Pul¬ 

verize  beef  bones,  mix  them  with  equal  parts  of  loam  and  calves’ 
hair  and  stir  the  mixture  into  a  thick  paste  with  water.  Apply  a 
coat  of  this  to  the  steel  and  place  it  in  a  crucible,  cover  this  with 
another,  fasten  the  two  together  with  wire  and  close  the  joint 
hermetically  with  clay.  Then  place  the  crucible  in  the  fire  and 
heat  it  slowly.  When  taken  from  the  fire  let  it  cool  by  placing  it 
in  ashes.  On  opening  the  crucible  the  steel  will  be  found  so  soft 
that  it  can  be  engraved  like  copper. 

New  Way  of  Annealing  Steel. — Heat  the  piece  as  slowly  as 
possible,  and  when  at  a  low  red  heat  put  it  between  two  pieces  of 
dry  board  and  screw  them  up  tight  in  a  vise.  The  steel  burns  its 
way  into  the  boards  and,  on  coming  together  around  it,  they  form 
a  practically  air-tight  charcoal-bed.  When  it  cools  off  the  steel  is 
apt  to  be  found  thoroughly  annealed. 

Two  Ways  of  Annealing  Steel. — It  may  be  heated  to  a  dull,  red 
heat,  covered  with  dry,  warm  sand  and  left  to  cool  slowly ;  or  heat 
and  cover  it  up  in  the  forge  fire,  and  leave  it  there  until  the  fire  is 
out  and  all  is  cold.  The  other  method  is  to  heat  the  steel  red  hot ; 
heat  gradually,  let  it  “soak,”  as  the  smiths  say,  until  it  is  evenly 
heated,  then  remove  it  from  the  fire  and  take  it  to  some  dark  place. 
Let  the  steel  cool  until  you  lose  sight  of  the  dull  red  in  the  dark  ; 
then  cool  off  in  cold  water.  A  good  “  dark  place”  may  be  made 
by  throwing  your  coat  over  a  barrel,  leaving  just  room  enough  to 
look  in  at  the  iron.  This  method  is  called  “  water  anneal,”  and 
is  based  upon  the  theory  that  steel  softens  when  cooled  at  a  certain 
temperature. 

Annealing  of  Bronze. — This  process  is  especially  employed  in 
the  preparation  of  alloys  for  cymbals,  tam-tams,  bells,  etc.  These 
alloys  themselves  are  brittle,  and  the  instruments  cast  from  them 
become  soft  and  sonorous  only  by  immersing  them  while  still  hot, 
in  cold  water,  then  hammering  and  finally  again  heating  and  slowly 
cooling.  While  steel  acquires  hardness  by  quenching,  a  copper-tin 
alloy  has  the  remarkable  property  of  becoming  sensibly  softer  and 


128 


THE  METAL  WORKER’S  HANDY-BOOK. 


more  ductile  when  quickly  cooled,  and  this  property  is  made  use 
of  by  heating  the  alloy  to  a  dark  red,  or,  in  case  of  thin  objects,  to 
the  melting  point  of  lead,  and  then  immersing  in  water.  The 
alloy  thus  treated  can  be  worked  under  the  hammer  and  stretched 
without  cracking  or  breaking. 

To  Harden  Copper. — Among  the  latest  methods  resorted  to  for 
hardening  copper  is  that  of  melting  together  and  stirring  until 
thoroughly  incorporated,  copper  and  from  i  to  6  per  cent,  of 
manganese  oxide.  The  other  ingredients  for  bronze  and  other 
alloys  may  then  be  added.  The  copper  thus  becomes  homogen¬ 
eous,  harder  and  tougher. 

To  Case-harden  Wrought-iron. — Wrought-iron  is  nearly  pure 
decarbonized  iron,  and  is  not  possessed  of  the  property  of  harden¬ 
ing.  But  articles  made  of  wrought-iron  may  be  exteriorly  con¬ 
verted  into  steel  and  afterwards  hardened.  The  process  is  called 
case-hardening,  and  only  differs  from  cementation  in  being 
carried  on  for  a  shorter  time;  it  is  seldom  necessary  to  convert  the 
iron  into  steel  more  than  -^g-inch  deep,  unless  where  great  stiffness 
as  well  as  hardness  is  required.  Case-hardened  iron  for  various 
purposes  is  better  than  steel ;  it  has  the  hardness  and  polish  of  steel 
externally,  with  a  core  of  soft  fibrous  iron  in  the  centre.  Prus- 
siate  of  potash  renders  iron  nearly  as  hard  as  steel,  by  heating  the 
iron  to  redness,  sprinkling  the  potash  finely  powdered  upon  it,  and 
then  plunging  the  iron  into  pure  cold  water ;  but  the  hardness  is 
confined  to  the  surface,  and  only  for  articles  not  exposed  to  much 
wear  can  a  sufficient  coating  of  steel  be  obtained  by  this  process. 
Greater  and  more  uniform  effect  is  produced  by  a  perfectly  tight 
box,  and  animal  charcoal  just  sufficiently  burnt  to  admit  of  being 
reduced  to  powder,  in  order  that  more  of  it  may  be  got  into  the 
box  with  the  articles  ;  bones  reduced  to  dust  answer  the  purpose 
equally  well.  The  box  should  be  of  plate-iron  not  less  than  yfa  to 
i^-inch  thick.  The  size  and  shape  differ  according  to  the  articles 
operated  upon.  The  box  is  furnished  with  an  iron  lid  with  two 
holes  pierced  in  it  for  drawing  testing  pieces  out,  if  required. 
The  box  may  be  strengthened  against  buckling  by  riveting  a  piece 
of  iron  about  ^-inch  square  inside  the  box  about  i  inch  from  the 


ANNEALING,  HARDENING,  TEMPERING. 


129 


top ;  this  will  also  answer  for  the  lid  to  rest  upon,  and  prevent  it 
from  pressing  upon  the  articles  when  expanded  by  the  heat.  Clay 
or  loam  put  between  this  iron  square  and  the  lid  makes  a  secure 
joint.  Two  holes  are  pierced  in  the  box  at  opposite  sides  just 
above  the  lid,  for  inserting  2  iron  pins,  and  making  the  joint  more 
secure.  Upon  a  small  scale  a  good  box  may  be  made  by  welding 
a  plug  into  one  end  of  a  piece  of  wrought-iron  pipe,  and  using  a 
loose  plug  for  the  opposite  end  ;  the  loose  plug  being  fastened  into 
place  with  an  iron  pin  passing  through  it  and  the  pipe,  and  luted 
with  clay.  For  a  small  article  a  box  may  be  formed  of  loam,  which 
is  gradually  dried  before  it  is  exposed  to  a  red  heat.  The  articles  be¬ 
ing  previously  finished,  except  polishing,  are  put  into  the  iron  box 
in  alternate  layers  with  the  animal  charcoal,  commencing  on  the 
bottom  of  the  box  with  charcoal  to  the  thickness  of  about  ^-inch ; 
upon  this  a  layer  of  the  articles  is  placed,  then  another  of  charcoal 
about  yi  of  the  first,  and  so  on  till  the  box  is  nearly  full,  finishing 
with  charcoal  about  the  thickness  of  the  first  layer,  leaving  room 
every  way  for  the  expansion  of  the  articles  by  the  heat,  otherwise 
they  will  bend  each  other  in  the  box.  The  packing  completed  the 
lid  is  put  on  and  the  box  luted.  The  whole  is  now  placed  in  a 
suitable  furnace ;  the  fire  must  not  be  urged,  as  the  contents  of  the 
box  require  to  be  very  gradually  and  uniformly  heated  to  redness 
and  retained  at  this  heat  for  the  period  required  for  the  depth  of 
steel  desired.  In  half  an  hour  after  the  contents  have  arrived  at 
the  proper  uniform  temperature,  the  depth  of  steel  will  scarcely  be 
the  thickness  of  a  dime ;  in  an  hour  about  double  the  depth,  and 
so  on.  To  tell  when  the  central  articles  arrive  at  the  proper  heat, 
a  testing  piece  is  withdrawn ;  if  it  be  not  sufficiently  heated,  the 
heating  must  be  continued  a  little  longer;  after  a  reasonable  time 
another  piece  is  withdrawn  and  if  sufficiently  hot,  hardened  in 
pure  cold  water;  it  can  then  be  broken  with  the  hammer,  and  the 
extent  of  the  carbonization  ascertained.  Different  kinds  of  iron 
absorb  carbon  unequally ;  consequently  the  testing  pieces  must  be 
made  of  the  same  kind  of  iron  as  the  articles.  The  more  homoge¬ 
neous  the  iron  the  more  equally  it  absorbs  carbon ;  consequently 
the  less  likely  it  will  be  to  alter  its  shape  in  hardening.  For  test- 
9 


130 


THE  METAL  WORKER’S  HANDY-BOOK. 


ing  pieces,  plain  pieces  of  the  same  kind  of  iron  as  the  articles 
may  be  used.  They  require  to  be  brightened  and  are  placed,  at 
the  time  of  the  packing  of  the  box,  in  the  central  part,  in  such  a 
manner  that  they  may  be  readily  pulled  out  through  the  holes  in 
the  lid,  either  by  a  piece  of  iron  wire  attached,  or  by  being  made 
long  enough  to  project  through  the  holes,  so  that  they  may  be 
gripped  with  pliers ;  the  holes  are  luted  the  same  as  other  parts. 
When  the  articles  are  sufficiently  converted,  the  box  is  drawn  from 
the  fire,  the  lid  taken  off,  and  the  contents  are  immersed  in  pure 
cold  water;  taken  out  when  cold  they  are  ready  for  polishing.  To 
prevent  rusting  the  articles  may  be  dried  by  riddling  in  a  sieve 
with  dry  sawdust,  after  which  they  are  wiped  with  a  greasy  cloth. 
If  the  articles  be  immersed  in  oil  instead  of  water,  they  will  be 
much  tougher  but  less  hard,  though  sufficiently  so  for  some  pur¬ 
poses.  It  is  not  necessary  to  immerse  them  direct  from  the  box, 
as  it  answers  equally  well  to  allow  them  to  remain  in  the  box  until 
cool,  and  then  reheat  them  in'an  open  fire  and  immerse  them  sepa¬ 
rately.  When  the  case-hardening  is  required  to  terminate  at  any 
particular  part  of  an  article,  the  part  needed  to  be  soft  may  be  bound 
with  thin  iron  wire  and  cased  with  loam.  This  prevents  the  iron 
from  absorbing  carbon  at  that  part.  The  loam  requires  to  be 
gradually  dried  upon  the  article  previous  to  putting  it  into  the 
box,  otherwise  it  will  crack.  Another  method  is  to  shrink  an  iron 
ring  or  collar  upon  the  part  not  required  to  be  case-hardened ;  but 
this  is  not  economical,  especially  when  many  articles  require  to  be 
treated.  To  save  the  trouble  of  shrinking  a  collar  on  and  getting 
it  off  again,  a  collar  somewhat  larger  in  diameter  than  the  article 
may  be  used,  the  space  between  being  filled  up  with  loam.  When 
a  collar  is  shrunk  upon  an  article  it  has  generally  to  be  cut  asunder 
to  be  taken  off,  and  is  in  future  useless ;  it  may  be  got  off  by  ham¬ 
mering,  but  this  will  damage  the  article  if  it  has  been  previously 
finished  except  polishing.  If  the  article  after  being  cemented  with 
the  carbon  be  immersed  in  water  previous  to  taking  off  the  collar, 
the  latter  will  become  hard  because  it  has  absorbed  carbon  ;  con¬ 
sequently  it  will  require  to  be  ground  on  the  grind-stone  before 
it  can  be  cut  off  by  the  chisel,  file  or  turning  tool.  In  some  in- 


ANNEALING,  HARDENING,  TEMPERING. 


131 


stances  when  case-hardening  is  to  terminate  at  a  particular  part, 
it  is  more  convenient  and  economical  to  postpone  the  finishing 
until  after  it  has  been  cemented  with  carbon.  Iron  cemented  with 
animal  charcoal,  however  skillfully  performed,  is  never  so  tenacious 
as  iron  cemented  with  wood  charcoal ;  consequently  it  is  unfit  for 
cutting  tools  as  it  will  not  take  a  fine  firm  edge,  and  it  is  ques¬ 
tionable  whether  it  could  be  made  suitable  for  the  purpose  by  pass¬ 
ing  through  the  process  of  forging  and  melting. 

To  Case-harden  A xle-arms.  — Instead  of  using  one  large  pan  and 
plunging  half  a  dozen  arms  into  it,  have  for  each  arm  a  round,  con¬ 
ical  box,  made  of  old  boiler  plate  inch  thick,  and  about  2  or  3 
inches  longer  and  about  2  inches  larger  in  diameter  inside  than 
the  arm.  Into  the  box  place  sufficient  animal  charcoal  to  raise 
the  collar  of  the  axle-arm  nearly  flush  with  the  top  of  the  box,  then 
surround  the  arm  with  the  charcoal  as  far  up  as  the  collar,  ramming 
it  firmly  down  as  you  proceed,  and  finally  cover  the  top  of  the 
charcoal  with  fire-clay,  taking  care  to  plaster  the  clay  well  round 
the  axle  and  the  edge  of  the  box.  The  furnace  is  a  small  rever¬ 
berating  one,  capable  of  holding  8  to  12  of  these  boxes  at  a  time. 
The  boxes  are  allowed  to  remain  in  the  furnace  1  to  2  hours,  accord¬ 
ing  to  the  size  of  the  axles,  etc. 

To  Harden  Cast-iro?i. — Mix  2  pounds  of  concentrated  sulphuric 
acid  and  2  ozs.  of  nitric  acid  with  2 *4  gallons  of  water.  Plunge 
the  article  at  a  cherry-red  heat  into  this  mixture.  The  surface 
becomes  very  hard. 

To  Harden  Cast-iron  in  a  Simple  Manner. — A  cast-iron  furnace, 
the  size  of  which  depends  on  that  of  the  casting,  is  employed.  It 
is  provided  front  and  back  with  doors,  so  that  a  small  carriage  can 
be  run  into  it.  The  arrangement  of  the  carriage  depends  on  the 
form  and  size  of  the  furnace,  as  well  as  on  the  objects  to  be 
hardened.  A  pipe  perforated  with  small  holes  enters  the  furnace, 
and  conveys  into  it  heated  steam.  The  objects  to  be  hardened,  espe¬ 
cially  cylinders,  are  allowed  to  rest  as  much  as  possible  with  their 
ends  upon  the  carriage.  For  small  objects,  such  as  cutlery,  a  small 
furnace  with  a  single  door  suffices.  It  must,  however,  always  be 
provided  with  a  carriage,  in  order  to  effect  cooling  off  as  quickly 


132 


THE  METAL  WORKER’S  IIANDY-BOOK. 


as  possible.  The  steam,  with  a  tension  of  two  atmospheres,  is 
taken  from  an  ordinary  boiler.  As  near  as  possible  to  the  furnace 
in  which  the  hardening  is  effected  is  another  furnace,  through  which 
the  steam  is  conducted  in  a  coil  of  pipe  with  a  diameter  of  15^ 
inches,  and  the  same  height.  Near  the  bottom  of  this  coil  is  a 
cock  for  the  discharge  of  condensed  water.  In  the  centre  the  coil 
is  lined  with  brick-work  ;  the  fire  in  the  furnace  circulates  around 
it  and  makes  it  red-hot,  so  that  the  steam  passing  through  it  to  the 
hardening  furnace,  becomes  superheated  and  suitable  for  hardening. 
For  objects  up  to  0.59  inch  thick,  one  hour  suffices  to  complete 
the  hardening. 

To  Quickly  and  Thoroughly  Harden  Soft  Iron. — Moisten  the 
object  with  water,  and  scatter  powdered  yellow  prussiate  of  potash 
upon  the  surface.  Then  heat  to  a  red  heat,  whereby  the  melting 
prussiate  of  potash  coats  the  surface  of  the  object ;  finally,  quench 
quickly  in  cold  water,  and  repeat  the  operation.  A  white  heat 
must  not  be  used,  the  iron  not  being  hardened  thereby  but,  on  the 
contrary,  oxidized.  Red  prussiate  of  potash  must  not  be  used,  the 
hardening  process  not  being  successful  with  it. 

To  Harden  Wrou gilt-iron  Parts  of  Machines. — The  most  suitable  - 
agents  for  this  purpose  are  old  leather,  hoofs,  horns,  and  bones; 
they  are  generally  charred,  coarsely  powdered,  and  thoroughly 
mixed.  A  box  of  cast-iron  or  strong  sheet-iron  serves  for  the 
reception  of  the  parts  to  be  hardened.  Upon  the  bottom  of  this 
box  is  first  placed  a  layer  of  the  cementing  agent,  about  1%  inch 
deep.  Upon  this  layer  are  placed  the  larger  parts,  in  such  a  man¬ 
ner  as  not  to  touch  each  other.  These  parts  are  then  covered 
inch  deep  with  the  cementing  powder,  special  care  being  had  that 
all  the  separate  parts  are  well  covered.  Upon  this  layer  of  cement¬ 
ing  agent  comes  again  a  layer  of  iron  parts,  then  again  a  layer  of 
cementing  agent,  and  so  on  until  the  box  is  full.  The  box  is  now 
covered  with  an  iron  lid,  and  the  latter  thoroughly  luted  with  clay. 
The  box  is  then  placed  upon  the  hearth,  and  surrounded  and 
entirely  covered  with  glowing  coals,  care  being  had  to  keep  up  a 
vigorous  fire,  so  that  the  entire  box  may  become  red-hot  at  one 
time.  Heating  is  continued  for  about  two  or  three  hours.  In 


ANNEALING,  HARDENING,  TEMPERING. 


133 


the  meanwhile  a  large  tub  full  of  fresh  water  is  placed  as  near  as 
possible  to  the  hearth.  In  order  to  keep  the  water  in  the  tub  as 
cold  as  possible,  it  is  advisable  to  arrange  so  that  fresh  water  may 
run  constantly  into  it.  The  fire  is  now  removed  from  the  lid,  the 
box  opened,  and  the  separate  articles  taken  out  with  tongs,  and 
suddenly  immersed  in  the  water,  where  they  remain  until  they  are 
quite  cooled  off.  The  waving  to  and  fro  of  the  iron  parts  and  a 
constant  supply  of  fresh  water  cannot  be  too  highly  recommended, 
because  all  the  labor,  time,  and  expense  would  be  lost  if  the  articles 
be  not  sufficiently  and  energetically  cooled  off.  In  immersing  the 
articles  in  the  water  care  must  be  had  not  only  to  manipulate  them 
rapidly,  but  they  must  also  be  introduced  lengthwise,  to  prevent 
them  as  much  as  possible  from  becoming  crooked.  Immersing  the 
articles  flat  would  at  once  make  them  crooked.  When  taken  from 
the  water  the  articles  are  dried  as  quickly  as  possible  upon  hot 
stones,  and  then  greased  with  oil. 

To  Harden  Steel  by  Pressure. — This  method  of  hardening  steel, 
invented  by  Clemandat,  of  Paris,  consists  in  heating  the  steel  to  a 
cherry  red,  and  then  subjecting  it  in  a  hydraulic  press  to  a  pressure 
of  up  to  2,000,  4,000,  and  6,ooo  lbs.  per  0.155  square  inch.  The 
steel  is  allowed  to  cool  between  the  press-plates  of  the  hydraulic 
press;  it  possesses  the  structure  and  qualities  of  steel  obtained  by 
tempering,  and  especially  a  very  fine  grain,  great  hardness  and 
density.  This  phenomenon  is  explained  by  the  simultaneous  action 
of  compression  and  cooling,  the  first  replacing  the  hammering  or 
rolling,  and  the  latter  the  immersion  in  a  cooling  fluid. 

To  Harden  Steel  in  Petroleum. — According  to  B.  Morgossy,  the 
articles  to  be  hardened  are  first  heated  in  a  charcoal  fire,  and,  after 
thoroughly  rubbing  with  ordinary  washing  soap,  heated  to  a  cherry 
red.  In  this  condition  they  are  quickly  plunged  into  petroleum ; 
ignition  of  the  petroleum  need  not  be  feared,  but,  of  course,  an 
open  flame  must  not  be  near  at  hand.  Articles  hardened  according 
to  this  method  show  no  cracks,  do  not  warp  in  the  least,  and  after 
hardening  remain  nearly  white,  so  that  they  can  be  blued  without 
previous  rubbing  with  emery. 

To  Harden  Steel  so  that  the  Exterior  is  Hard  and  the  Interior 


134 


THE  METAL  WORKER’S  IIANOY-BOOK. 


Soft. — Pulverize  and  mix  yellow  prussiate  of  potash  3  parts  ;  borax, 
1  ;  saltpetre,  1 ;  and  sugar  of  lead,  fi.  Heat  the  steel  to  be 
hardened  to  a  red  heat,  and  scatter  the  powder  over  it.  Then 
replace  the  steel  in  the  fire,  and  when  it  has  attained  the  proper 
degree  of  heat,  cool  it  off  in  cold  rain-water.  Steel  cooled  off 
according  to  this  method  is  very  tenacious. 

To  Harden  Small  Drills. — The  drill  being  filed  the  right  size 
(the  edge  must  not  be  hammered  flat),  it  is  moderately  heated  with¬ 
out  becoming  red,  and  then  plunged  into  borax,  whereby  it  becomes 
incrusted  with  borax  and  the  air  is  excluded.  The  drill  may  now 
be  hardened  by  heating  to  cherry-red,  and  finally  plunged  into  a 
piece  of  borax,  or,  what  is  still  better,  into  mercury,  care  being  had 
not  to  inhale  the  vapor.  The  borax  yielding  to  the  heat  of  the 
drill,  melts  and  cools  off  the  drill.  The  results  of  various  experi¬ 
ments  of  cooling  off  the  drill  incrusted  with  borax  in  water,  oil,  etc., 
were  not  so  favorable  as  plunging  it  into  borax  or  mercury.  The 
drill  becomes  extraordinarily  hard,  without  being  brittle,  so  that 
articles  which  cannot  be  worked  with  drills  hardened  in  the  ordinary 
manner  can  be  drilled  with  it.  Watchmakers  generally  use  broken 
broaches  for  such  small  drills,  they  being  under  the  impression  that 
they  are  of  the  best  steel ;  such,  however,  is  not  always  the  case,  the 
broaches  having  frequently  been  burnt  in  hardening;  consequently 
the  steel  is  spoilt  for  such  purposes,  and  hence  it  is  advisable  to 
take  new  round  steel  wire. 

Hardening-water  for  Steel. — Generally  water  at  a  temperature  of 
from  50°  to  770  F.  is  used  for  quenching  the  steel  in  hardening; 
the  water  should,  however,  not  be  too  cold,  as  otherwise  cracks  or 
fissures  are  formed  in  the  steeU  Watchmakers  and  jewelers  use 
hardening-water  of  320  F.,  and  frequently  ice  for  very  small 
articles.  Water  containing  soap  in  solution  is  unsuitable  for  hard¬ 
ening. 

Fluids  for  Hardening  Steel  Articles. — I.  Rosin,  10  lbs.  ;  train 
oil,  5  lbs.  ;  lard,  2  lbs.  ;  and  assafoetida,  4^  ozs.  By  using,  this 
bath  steel,  even  if  frequently  heated,  retains  its  former  character¬ 
istics. 

II.  Especially  Used  for  Hardening  Cutlery. — Refined  borax, 


ANNEALING,  HARDENING,  TEMPERING. 


135 


2  lbs.;  sal-ammoniac,  4  lbs.;  water,  3  quarts;  and  French  red 
wine,  4  ozs.  . 

III.  Sal-ammoniac,  3  lbs.  ;  potash,  1  lb.  ;  water,  4  gallons ;  red 
wine  or  vinegar,  1^  pints;  and  tartaric  acid,  1  lb. 

Hardening  Compound  for  Steel. — Pulverize  3  parts  by  weight  of 
prussiate  of  potash,  1  of  borax,  1  of  saltpetre,  and  of  sugar  of 
lead,  and  intimately  mix  the  whole.  After  heating  the  steel  to  be 
hardened  to  a  red  heat,  take  it  from  the  fire  and  scatter  the  powder 
over  it.  The  steel  is  then  replaced  in  the  fire,  and  after  having 
been  brought  to  the  required  degree  of  heat,  cooled  in  cold  rain¬ 
water. 

Hardening  Mixture ,  Patented  by  J.  Robb ,  of  Dundee ,  Forfar¬ 
shire. — The  red-hot  iron  is  plunged  into  a  mixture  of  yellow  prus¬ 
siate  of  potash,  1  lb.  ;  rock  salt,  2  lbs.  ;  bone-dust,  lbs.  ;  char¬ 
coal,  2  ozs.  ;  and  hydrochloric  acid,  pint.  The  metal  is  then 
again  heated,  once  more  plunged  into  the  mixture  for  a  few  minutes, 
and  then,  while  still  hot,  immersed  in  cold  water.  The  propor¬ 
tions  of  the  above  substances  may  vary,  and,  in  some  cases,  lime 
may  be  added. 

To  Avoid  Cracks,  Curving,  and  Warping  in  Hardening  Steel. — 
The  following  directions  should  be  observed:  1.  Thin  flat  pieces 
should  be  immersed,  edge  foremost,  with  uniform  velocity.  If  al¬ 
lowed  to  touch  the  water  with  the  broad  surface  they  would  warp. 
2.  Articles  considerably  thicker  on  one  side  than  on  the  other,  for 
instance,  razors,  must  be  immersed  with  the  thick  side  foremost,  as 
otherwise  the  thin  side  would  show  cracks.  3.  The  article  is  to  be 
immersed  in  the  hardening-water  as  far  as  it  has  been  made  red 
hot ;  otherwise,  a  crack  is  formed  on  the  place  of  immersion.  4. 
In  hardening  cast-iron  articles  tipped  with  steel,  it  must  be  taken 
into  consideration  that  cast-iron  contracts  more  strongly  than  steel, 
and  that  consequently  the  article  would  every  time  curve.  To 
avoid  this,  curve  the  article  before  hardening  to  the  opposite  side. 

How  to  Harden  Thin  Steel  Plates. — Provide  two  pieces  of  iron 
about  6"  x  6"  x  1",  with  one  surface  on  each  block  planed,  spread 
a  liberal  supply  of  good  sperm  oil  on  each  planed  surface,  place  the 
blocks  near  by  in  level  position  to  insure  an  even  thickness  of  oil, 


13(3 


THE  METAL  WORKER’S  HANDY-BOOK. 


and  keep  the  blocks  cool.  Immerse  the  steel  plates  in  molten  lead,  as 
far  as  they  are  required  to  be  hardened ;  when  a  red  heat  is  obtained, 
drop  the  piece  quickly  upon  the  oiled  surface  of  one  of  the  iron 
blocks,  and  simultaneously  lay  the  other  iron  block  upon  the  work; 
when  cool,  they  will  be  found  true.  This  system  has  been  succcess- 
fully  used  for  years  for  hardening  thin  steel  tools. 

Another  method  is  as  follows :  Sheet  steel  inch  thick  can  be 
successfully  hardened  between  two  cast-iron  blocks  placed  in  a 
screw-press  or  any  kind  of  hand-press.  Holes  should  be  drilled  in 
the  corners  of  the  lower  block  for  spiral  springs  of  sufficient  power 
to  keep  the  blocks  apart. 

The  steel  should  be  heated  (a  small  gas  furnace  is  preferable), 
and  quickly  inserted  between  the  blocks,  and  pressed  hard  until 
cool  enough  to  insure  against  drawing  temper.  A  good  plan  is  to 
have  two  pieces  in  the  furnace  at  once,  and  allow  one  to  cool  while 
the  other  is  heating. 

To  draw  the  temper,  brighten  part  of  the  piece  on  an  emery- 
wheel,  and  then  run  them  together  with  sand  in  a  sheet-iron 
tumbler,  under  which  is  a  fire  (a  few  gas-jets  are  the  best),  until 
the  desired  color  is  obtained. 

Hardening  of  Steel  According  to  Newton  and  Ames. — According 
to  the  patent  considerable  hardness  can  be  imparted  to  the  surface 
of  steel  objects  by  mechanical  means.  The  process  consists  in 
gently  pressing  a  slowly  revolving  steel  object  against  a  quickly 
revolving  emery  wheel.  Besides  its  revolution  the  object  to  be 
hardened  has  a  horizontal  motion  in  a  lateral  direction,  so  that 
with  each  revolution  it  is  pushed  sideways  nearly  0.78  inch.  The 
hardening  process  is  finished  when  the  object  is  out  of  reach  of  the 
emery  wheel.  The  hardened  layer  is  about  0.03  millimetre  thick, 
and  is  capable  of  resisting  the  best  tools  hardened  in  the  ordinary 
manner. 

To  Harden  Steel  in  Sealing-wax. — Watch  and  clock-makers  and 
engravers  harden  their  steel  in  sealing-wax.  The  article  is  heated 
to  a  white-heat  and  thrust  into  sealing-wax,  allowed  to  remain  for  a 
second,  then  withdrawn,  and  again  inserted  in  another  part  of  the 
wax.  This  treatment  is  continued  till  the  steel  is  cold  and  will  no 


ANNEALING,  HARDENING,  TEMPERING. 


137 


longer  enter  the  sealing-wax.  The  extreme  hardness  of  steel  thus 
prepared  enables  one  to  engrave  or  drill  steel  hardened  by  other 
processes,  the  drilling  or  engraving  tool  being  first  dipped  in  oil 
of  turpentine. 

To  Harden  Springs  and  Saws. — Springs  and  saws  are  generally 
hardened  in  various  compositions  of  oil,  suet,  wax  and  other 
ingredients,  which,  however,  lose  their  hardening  property  after  a 
few  weeks’  constant  use.  The  saws  are  heated  in  long  furnaces  and 
then  immersed  horizontally  and  edgeways  in  a  trough  containing 
the  composition  ;  two  troughs  are  commonly  used,  the  one  until  it 
gets  too  warm,  then  the  other  for  a  period,  and  so  on  alternately. 
Part  of  the  composition  is  wiped  off  the  saws  with  a  piece  of 
leather,  when  they  are  removed  from  the  trough,  and  they  are  then 
heated  one  by  one  over  a  clear,  coke-fire  until  the  grease  ignites ; 
this  operation  is  called  “ blazing  off." 

The  composition  used  by  an  experienced  saw-maker  is  2  lbs.  of 
suet  and  %  lb.  of  beeswax  to  every  gallon  of  whale  oil ;  these 
are  boiled  together,  and  will  serve  for  thin  works  and  most  kinds 
of  steel.  The  addition  of  black  resin  to  the  extent  of  about  1  lb. 
to  the  gallon  makes  it  serve  for  thicker  pieces  and  for  those  which 
did  not  become  hard  by  the  first  application  ;  but  the  resin  should 
be  added  with  judgment  or  the  objects  will  become  too  hard  and 
brittle.  The  composition  is  useless  when  it  has  been  constantly 
employed  for  about  a  month  ;  the  period  depends,  however,  on  the 
extent  to  which  it  is  used.  The  trough  should  be  thoroughly 
cleaned  out  before  a  new  mixture  is  placed  in  it. 

The  following  composition  is  recommended  :  Spermaceti  oil, 
20  gallons ;  bee^suet,  rendered,  20  lbs.  ;  neat’s-foot  oil,  1  gallon ; 
pitch,  1  lb. ;  black  resin,  3  lbs.  The  last  two  articles  must  be 
previously  melted  together,  and  then  added  to  the  other  in¬ 
gredients.  The  whole  is  then  heated  in  a  suitable  iron  vessel  with 
a  close  cover  until  the  moisture  is  entirely  evaporated,  and  the 
composition  will  take  fire  on  a  flaming  body  being  presented  to  its 
surface.  The  flame  must  be  instantly  extinguished  by  putting  on 
the  cover  of  the  vessel. 

When  the  saws  are  needed  to  be  rather  hard,  but  little  of  the 


133 


THE  METAL  WORKER’S  HANDY-BOOK. 


grease  is  burnt  off ;  when  milder,  a  larger  portion ;  and  for  a 
spring  temper,  the  whole  is  allowed  to  burn  away.  When  the 
work  is  thick  or  irregularly  thick  and  thin,  as  in  some  springs,  a 
second  and  third  dose  are  burnt  off  to  insure  at  all  parts  equality 
of  temper. 

Gun-lock  springs  are  sometimes  literally  fried  in  oil  for  a  con¬ 
siderable  time  over  a  fire  in  an  iron  tray;  the  thick  parts  are  then 
sure  to  be  sufficiently  reduced,  and  the  thin  parts  do  not  become 
the  more  softened  from  the  continuance  of  the  blazing  heat. 

Springs  and  saws  appear  to  lose  their  elasticity  after  hardening 
and  tempering  from  the  reduction  and  friction  they  undergo  in 
grinding  and  polishing.  Towards  the  conclusion  of  the  manu¬ 
facture  the  elasticity  of  the  saw  is  restored  principally  by  hammer¬ 
ing  and  partially  by  heating  over  a  clear,  coke-fire  to  a  straw-color. 
The  tint  is  removed  by  very  dilute  hydrochloric  acid,  after  which 
the  saws  are  well  washed  in  clear  water  and  dried. 

Watch  springs  are  hammered  out  of  round  steel  wire  of  suitable 
diameter  until  they  fill  the  gauge  for  width,  which  at  the  same 
time  insures  equality  of  thickness ;  the  holes  are  punched  in  their 
extremities,  and  they  are  trimmed  on  the  edge  with  a  smooth  file. 
The  springs  are  then  tied  up  with  binding  wire,  in  a  loose  open 
coil,  and  heated  over  a  charcoal  fire  upon  a  perforated  revolving 
plate ;  they  are  hardened  in  oil  and  blazed  off. 

The  spring  is  now  distended  in  a  long  metal  frame  similar  to 
that  used  for  a  saw  blade,  and  ground  and  polished  with  emery 
and  oil  between  lead  blocks.  By  this  time  its  elasticity  appears 
quite  lost,  and  it  may  be  bent  in  any  direction  ;  its  elasticity  is, 
however,  entirely  restored  by  a  subsequent  hammering  on  a  very 
bright  anvil. 

The  coloring  is  done  over  a  flat  plate  of  iron  or  hood,  under 
which  a  small  spirit-lamp  is  kept  burning.  The  spring  is  con¬ 
tinually  drawn  backwards  and  forwards  about  2  or  3  inches  at  a 
time,  until  it  assumes  the  orange  or  deep  blue  tint  throughout,  ac¬ 
cording  to  the  taste  of  the  purchaser.  By  many  the  coloring  is 
considered  to  be  a  matter  of  ornament  and  not  essential.  The 
last  process  is  to  coil  the  spring  into  the  spiral  form  that  it  may 


ANNEALING,  HARDENING,  TEMPERING. 


139 


enter  the  barrel  in  which  it  is  to  be  contained.  This  is  done  by  a 
tool  with  a  small  axis  and  winch-handle  and  does  not  require  heat. 

The  balance  springs  of  marine  chronometers  are  wound  into  the 
square  thread  of  a  screw  of  the  appropriate  diameter  and  coarse¬ 
ness.  The  two  ends  of  the  spring  are  retained  by  side  screws,  and 
the  whole  is  carefully  enveloped  in  platinum  foil  and  tightly  bound 
with  wire.  The  mass  is  next  heated  in  a  piece  of  gun-barrel  closed 
at  the  one  end  and  plunged  into  oil,  which  hardens  the  spring  al¬ 
most  without  discoloring  it,  owing  to  the  exclusion  of  the  air  by 
the  close  platinum  covering  which  is  now  removed,  and  the  spring 
is  let  down  to  the  blue  before  removal  from  the  screwed  block. 

The  balance  or  hair  springs  of  the  best  watches  are  hardened  in 
the  coil  upon  a  plain  cylinder  and  are  then  curled  into  the  spiral 
form  between  the  edge  of  a  blunt  knife  and  the  thumb,  the  same 
as  in  curling  up  a  narrow  ribbon  of  paper  or  the  filaments  of  an 
ostrich  feather. 

In  hardening  bow-springs  for  all  kinds  of  vehicles  they  are 
heated  by  being  drawn  backwards  and  forwards  through  an  ordi¬ 
nary  forge  fire,  built  hollow,  and  then  they  are  immersed  in  a 
trough  of  plain  water.  In  tempering  them  they  are  heated  until 
the  black  red  is  just  visible  at  night ;  by  daylight  the  heat  is  de¬ 
noted  by  its  making  a  piece  of  wood  sparkle  when  rubbed  on  the 
spring,  which  is  then  allowed  to  cool  in  the  air. 

To  Harden  Files  and  Other  Steel  Instruments. — The  files,  etc., 
are  first  coated  with  a  paste  prepared  by  boiling  glue  and  salt  in 
yeast  and  thickened  by  an  addition  of  wood  charcoal  and  graphite 
(black  lead).  Upon  this  coat  is  scattered  a  coarse  powder  consist¬ 
ing  of  a  mixture  of  horn,  wood  charcoal  and  common  salt.  A  solid 
crust  is  formed  upon  the  files,  which  protects  them  from  a  dis¬ 
placement  of  the  cuts  by  the  metal  and  conveys  to  them  oxygen 
while  being  heated.  For  tempering  the  files  are  brought  into  a 
lead-bath.  To  prevent  the  oxidation  of  the  lead  on  the  surface  a 
mixture  of  potash,  soda  and  tartar  is  scattered  upon  it.  The  files 
remain  in  the  bath  5  to  8  minutes,  according  to  their  thickness,  and 
are  then  immersed  in  water. 

To  Harden  Steel  Instruments. — The  instrument  is  first  brought  to 


140 


TIIE  METAL  WORKER’S  IIANDY-BOOK. 


a  cherry  heat,  if  possible  in  a  charcoal  fire.  The  edge  is  then 
quickly  dipped  in  a  mixture  of  black  soap  and  finely  pulverized 
yellow  prussiate  of  potash,  taken  out  and  quenched,  but  only  half  of 
it,  in  clear  water,  in  which  it  remains  until  cold.  Only  in  this  man¬ 
ner  can  the  warping  of  the  object  be  prevented  and  the  edge  thor¬ 
oughly  hardened,  while  the  remaining  portion  which  may  have  to 
serve  for  securing  the  instrument  in  a  handle  remains  sufficiently 
soft  to  allow  of  holes  being  drilled  in  it. 

To  Harden  Tools. — The  following  process  has  the  advantage  of 
enabling  one  to  give  to  castings  any  desired  degree  of  hardness 
without  their  warping  or  becoming  too  hard  and  brittle  in  the  in¬ 
side.  For  the  hardening  agent  take  Peruvian  bark,  500  parts  by 
weight  ;  hartshorn  shavings,  50  ;  common  salt,  25  ;  yellow  prussiate 
of  potash,  15  ;  saltpetre,  15 ;  and  black  soap,  100.  Spread  out  the  soap 
in  a  layer  about  o.  39  inch  deep,  and  after  scattering  upon  it  the  pul¬ 
verized  mixture  of  the  other  five  ingredients  thoroughly  knead  the 
paste  thus  formed.  This  kneading  should,  however,  not  be  con¬ 
tinued  longer  than  is  absolutely  necessary  to  form  the  mass  into  a 
stick  of  about  2  inches  diameter.  After  about  24  hours’  drying 
the  mass  is  ready  for  use.  In  superficial  hardening  of  punches, 
twisted  augers,  etc.,  care  must  be  had  to  heat  the  cast-steel  article 
only  dark  red,  i.  <?.,  only  to  such  an  extent  that  on  cooling  in  cold 
water  its  hardness  is  not  increased.  Then  coat  the  portions  to  be 
hardened  with  the  hardening  agent  and  cool  off  the  object.  The 
interior  as  well  as  all  portions  not  coated  remains  perfectly  soft  and 
tough,  while  the  prepared  portions  become  as  hard  as  glass.  To 
accurately  hit  the  correct  degree  of  heating  the  cast-steel  it  is 
recommended  to  make  in  the  above  manner  several  experiments 
with  a  round  steel  wire  about  y2  inch  thick.  By  testing  the  frac¬ 
ture  with  a  file  the  condition  of  the  interior  is  then  ascertained. 

Hardening  Gun-barrels  According  to  Neunert. — The  barrel  to  be 
hardened  is  placed  in  a  gas-pipe  of  suitable  size,  the  lower  end  of 
which  is  made  narrow  to  prevent  the  barrel  from  slipping  out  while 
in  a  vertical  position.  Several  such  pipes  containing  gun-barrels 
are  then  heated  to  a  red  heat  in  a  reverberatory  furnace,  when  some 
hardening  compound  is  thrown  into  every  barrel.  The  pipes  are 


ANNEALING,  HARDENING,  TEMPERING. 


141 


now  taken  from  the  furnace,  placed  in  a  vertical  position  under  a 
hose  and  hardening  water  is  passed  through  each  barrel  under  a 
pressure  of  yi  to  ^  atmosphere.  It  is  very  advantageous  to  add  a 
small  quantity  of  sulphuric  and  nitric  acids  to  the  hardening  water. 

To  Harden  the  Bores  of  Musket-barrels. — The  barrels  are  secured  in 
a  frame  so  that  they  can  be  turned  during  heating  to  prevent  warping. 
Through  the  barrels  heated  to  a  red  heat  is  then  conducted  a  jet  of 
a  solution  of  potassium  ferrocyanide,  whereby  the  bore  acquires  con¬ 
siderable  hardness  in  consequence  of  saturation  with  carbon  and 
nitrogen,  while  the  chemical  constitution  of  the  rest  of  the  metal 
is  unchanged. 

The  same  object  is  attained  by  a  less  costly  method,  as  follows: 
The  barrel  is  filled  with  nitrogenous  (animal)  waste,  such  as  leather, 
hair,  horns,  hoofs,  etc.,  suitably  comminuted,  or  with  a  mixture  of 
yellow  prussiate  of  potash,  borax  and  corn  meal,  or  yellow  prus- 
siate  of  potash  and  charcoal.  Both  ends  of  the  bore  are  then 
closed  by  a  cork  or  clay  and  the  barrel  is  heated  as  uniformly  as 
possible. 

Adam  Schaefer' s  Fluid for  Hardening  Steel,  which  serves  to  im¬ 
prove  the  quality  of  many  varieties  of  steel,  consists  principally  of 
ordinary  resins,  linseed  oil,  glycerin  and  powdered  wood  charcoal, 
the  ingredients  being  intimately  mixed  and  the  mixture  heated.  The 
steel  at  a  bright  cherry-red  heat  is  dipped  in  the  fluid  and,  after 
cooling  in  it,  again  heated  and  subjected  to  one  of  the  usual 
methods  of  hardening  by  water,  oil  or  melted  compositions  of 
metal.  The  effect  produced  by  this  process  is  said  especially  to 
show  itself  in  burnt  cast-steel,  which  thereby  regains  its  original 
qualities,  while  softer  varieties  of  steel  acquire  the  advantages  of 
cast-steel.  Tools  made  from  Bessemer  steel,  which  cannot  be 
hardened  in  the  usual  manner,  may,  after  passing  through  the 
above-described  process,  be  used  for  cutting  castings  which  fre¬ 
quently  resist  the  best  tools  made  of  tungsten  steel. 

To  Harden  Copper. — To  impart  to  copper  and  copper  alloys 
greater  hardness  and  tenacity  the  following  process  is  recommended : 
Melt  the  copper  with  i  to  6  per  cent,  of  oxide  of  manganese  (the 
naturally  occurring  black  oxide  will  do)  in  a  crucible,  stir  thor- 


142 


THE  METAL  WORKER’S  HANDY-BOOK. 


oughly  and  after  carefully  removing  the  scum  formed  pour  it  out. 
The  same  process  is  followed  in  the  preparation  of  brass,  the  nec¬ 
essary  quantity  of  zinc  being  added  to  the  melted  copper  and  oxide 
of  manganese.  Though  chiefly  used  for  brass  alloys,  the  process  is 
suitable  for  all  alloys  of  which  copper  forms  the  principal  constituent. 

To  Harden  Zinc. — According  to  Brignol,  Fargon  and  Delpierre’s 
method  from  1.76  to  3.52  ozs.  of  sal-ammoniac  per  pound,  accord¬ 
ing  to  the  hardness  desired,  are  brought  into  the  melted  metal. 
Zinc  thus  treated,  it  is  said,  can  be  worked  with  the  turning-tool 
and  file,  and  can  in  many  cases  be  advantageously  substituted  for 
bronze. 

Hardening  Compound. — Pulverize  and  mix  intimately  1  part 
each  of  pulverized  yellow  prussiate  of  potash,  purified  saltpetre 
and  calcined  cows’  hoofs,  3^  of  gum  arabic,  3^  of  aloes  and  y2  of 
common  salt.  Scatter  the  compound  upon  the  steel  while  at  a  red 
heat,  and  upon  the  wrought-iron  while  at  a  white  heat,  and  burn  it 
thoroughly  in. 

New  Case-hardening  Compound. — This  compound  is  very  effica¬ 
cious  for  case-hardening  iron.  It  consists  of  lampblack,  16  parts; 
sal-soda,  18 ;  muriate  of  soda,  4;  and  black  oxide  of  manganese,  1. 

Agents  for  Hardening,  Improving  and  Welding  Steel. — The  so- 
called  “ Steel-powder  No.  1,”  prepared  by  A.  Schenker’s  Wittwe  at 
Rhein  felden,  is  claimed  to  possess  the  property  of  improving  steel; 
it  may  also  serve  as  welding  powder  and  to  restore  burnt  steel  to 
its  original  condition  and  hardness.  This  powder  consists  of  jA, 
borax,  ammonium  chloride  and  j/3  organic  substance  (resin, 
white  pitch)  with  a  trace  of  silicic  acid.  By  the  addition  of  this 
powder  during  forging,  turning  tools,  etc.,  are  much  improved. 

Powder  No.  2,  for  Welding  Cast- steel  with  the  Assistance  of  Heat, 
consists  of  ferric  oxide,  25  per  cent.  ;  ammonium  chloride,  15  per 
cent.  ;  silicic  acid,  50  per  cent. ;  and  carbonate  of  lime,  io-  per 
cent. 

Powder  No.  3,  for  Hardening  Steel,  is  claimed  to  restore  to 
“  fatigued  ”  steel  its  original  strength.  It  consists  of  48  per  cent, 
nitre,  58  per  cent,  organic  substance  (very  likely  pulverized  hoofs) 
and  about  2  per  cent,  silicic  acid. 


ANNEALING,  HARDENING,  TEMPERING. 


143 


Powder  No.  4,  the  so-called  '•'■Iron  Powder,"  is  used  for  super¬ 
ficially  hardening  wrought  and  ingot  iron.  It  is  claimed  that  by 
scattering  it  three  times  upon  the  articles  and  burning  off,  as  great 
a  depth  of  steel  is  obtained  as  by  case-hardening  for  six  hours.  It 
consists  of  15  per  cent,  sodium  chloride,  25  per  cent,  pyrolusite, 
10  per  cent,  sodium  carbonate  and  50  per  cent,  organic  substance. 
Color,  reddish-brown.  This  powder  is  also  suitable  for  case- 
hardening. 

The  following  agents  are  brought  into  commerce  by  Karl  Kilpfer, 
Biel,  Switzerland :  Hardening  mass  A  is  a  brown-red  mass  drawing 
threads;  it  consists  very  likely  of  train  oil,  50  parts;  ordinary 
colophony,  40;  and  turpentine  resin,  10.  It  is  used  for  hardening 
as  well  as  for  restoring  burnt  steel.  The  tools  or  other  articles  to 
be  hardened  are  brought  to  a  red  heat  in  a  charcoal  fire  and 
plunged  into  the  mass  until  black.  They  are  then  returned  with¬ 
out  previous  cleaning  to  the  fire  and  when  at  a  red  heat  hardened 
in  the  hardening-water  B.  This  is  prepared  by  boiling  pure  well- 
water  in  an  uncovered  vessel,  pouring  it  off  when  cold  from  the 
sediment  and  adding  for  each  quart  of  water  14  drachms  of  a  mix¬ 
ture  consisting,  according  to  analysis,  of  40  per  cent,  nitre,  59  per 
cent,  ammonium  chloride  and  a  trace  of  sodium  sulphate  (the 
latter  perhaps  only  as  an  impurity). 

The  “ Steel-hardening  Powder  C"  consists  of  5  five  per  cent, 
nitrate  of  soda,  15  per  cent,  ammonium  chloride,  25  per  cent,  yel¬ 
low  prussiate  of  potash  and  55  per  cent,  organic  substance  (pul¬ 
verized  hoofs). 

The  li  Hardening-water  D"  consists  of  a  concentrated  solution 
of  salts,  the  same  as  B,  4  lbs.  of  powder  being  taken  to  every  10 
quarts  of  water  and  when  dissolved  1  lb.  of  pure  sulphuric  acid 
added. 

Tempering  Colors  of  Steel. — By  superficial  oxidation  tempering 
colors  are  formed  in  hardening  steel,  which  serve  as  a  guide  as  re¬ 
gards  the  temperature  and  degree  of  hardness. 


144 


THE  METAL  WORKER’S  II ANDY-BOOK. 


Temperature. 

Color. 

428  0  F . 

Pale  yellow. 

Light  straw-yellow. 

Straw-yellow. 

Brown-yellow. 

Brown  with  purple  stains 
Purple 

Pale  blue. 
Corn-flower-blue. 

Dark  blue. 

44Q.6  “  . 

469.4  “  . 

491.0  “  . 

COQ.O  “  . 

440.6  “  . 

qqo.4  “  . 

CCn.4  “  . 

600.8  “  . 

The  steel  is  suitable  for 


Surgical  instruments. 

Razors  and  pen-knives. 

Scissors,  chisels. 

Axes,  planes,  irons,  bread-knives. 
Table-knives, 

Sword-blades,  watch-springs. 
Fine  saws,  drills,  fencing-foils. 
Hand-saws. 


I 


For  Baths  Used  by  Cutters  and  Others  in  Tempering  and  Heatijig 
Steel  Articles,  Parkes  and  Martin  propose  the  following  alloys  : 


No. 

Use. 

Composition. 

Melting 
points. 
Degrees  F 

Lead. 

Parts. 

Tin 

Paris. 

1 

Lancets . 

7 

4 

420 

2 

Other  surgical  instruments . 

V/z 

4 

43° 

3 

Razors . 

8 

4 

442 

4 

Pen-knives . 

S'A 

4 

450 

5 

Knives,  scalpels,  etc . 

IO 

4 

470 

6 

Chisels,  garden-knives . 

14 

4 

490 

7 

Hatchets . 

19 

4 

509 

8 

Table-knives . 

30 

4 

530 

9 

Swords,  watch-springs . 

48 

4 

55° 

IO 

Large  springs,  small  saws . 

50 

4 

558 

II 

Handsaws . 

Oil,  boiling. 

600 

12 

Articles  of  low  temper . 

4 

612 

Effect  of  Temperature  on  Steel. — At  570°  F.  a  dark  blue  color  is 
produced  upon  polished  steel,  which  is  changed  to  a  pale  blue  at 
590°  F.  Oil  or  grease  of  any  kind  will  answer  for  drawing  the  temper 
of  cutlery.  The  temper  for  lancets  is  obtained  at  430°  F.,  axes 
at  500°  F.,  swords  and  watch-springs  at53o°  F., small  saws  at  570°  F. 
and  large  saws  at  590°  F.  Copper-colored  spots  are  not  pro¬ 
duced  by  tempering,  but  they  may  be  obtained  on  the  polished 


ANNEALING,  HARDENING,  TEMPERING. 


145 


surface  of  steel  by  immersing  the  article  in  a  solution  of  sulphate 
of  copper. 

To  Temper  Steel  by  Electricity. — Among  the  more  recent  uses  to 
which  electricity  has  been  applied  is  that  for  tempering  watch-springs 
and  other  forms  of  spring  steel,  whether  in  the  form  of  ribbon  or  wire. 
The  steel  is  wound  on  a  spool,  whence  it  passes  down  through  a 
bath  of  oil.  An  electric  current  is  sent  through  the  wire  of  such 
strength  as  to  keep  it  at  the  proper  redness  to  answer  the  desired 
requirements  of  temper.  As  the  heating  is  not  done  in  contact 
with  the  air,  but  is  entirely  beneath  the  surface  of  the  oil,  there  is 
no  trouble  from  blistering,  as  in  the  ordinary  methods.  The  final 
temper  is  drawn  in  the  same  manner,  and  the  wire  or  ribbon  is 
finished  by  means  of  rolls.  The  process  is  also  applied  to  a  num¬ 
ber  of  springs  beside  those  for  watches,  including  piano  wires.  In 
all  cases  the  process  can  be  controlled  to  a  nicety,  both  as  to  ex¬ 
act  temper  and  its  uniformity  through  the  wire. 

To  Temper  Mining-picks. — When  ready  for  hardening,  the  pick 
should  be  heated  in  the  blaze  of  a  charcoal  fire  until  red  hot  and 
then  plunged  into  cold  rain  water  and  kept  there  until  it  is  nearly 
cold.  Some  blacksmiths  use  salt-water.  No  salts  of  any  kind 
should  exist  in  the  water,  but  the  water  should  be  cold.  If  it  is 
warm  throw  in  a  little  ice  and  the  tempering  will  be  all  the  better. 
Pure  soft  water  for  hardening  will  make  a  tougher  pick  and  one  less 
liable  to  crack  at  the  edges  than  where  salt-water  is  used.  The 
last  hammering  of  a  pick  should  always  be  given  on  the  flat  sides, 
across  close  to  the  edges,  and  then  up  each  side  about  an  inch.  By 
doing  so  the  corners  wiU  be  less  liable  to  crack. 

To  Temper  Taps  and  Dies. — The  great  difficulty  in  hardening 
tools  is  principally  their  liability  to  twist  or  get  out  of  truth; 
secondly,  cracking  (especially  if  large)  after  hardening ;  thirdly, 
getting  the  right  temper.  First,  carefully  select  your  steel ;  let  it 
be  of  the  best  cast,  with  a  medium  grain  ;  a  fine-grained  steel  will 
break  when  much  less  force  is  applied  than  a  coarser-grained,  and 
although  it  will  take  a  keener  edge  it  will  not  resist  the  strain  re¬ 
quired  by  a  tap  or  rimer.  Next  centre  it  and  turn  off  the  scale 
and  soften.  The  object  of  softening  after  the  scale  is  removed  is 
10 


146  THE  METAL  WORKER’S  IIANDY-BOOK. 

to  make  the  grain  of  the  steel  equal  throughout  ;  if  it  be  softened 
with  the  scale  on  it  will  generally  cast.  To  soften  enclose  the  ar¬ 
ticles  in  a  piece  of  gas-tube,  filling  up  with  wrought-iron  turnings 
and  plugging  the  ends  with  clay,  making  the  whole  red  hot  and 
allowing  it  to  cool  very  slowly,  i.  e.,  leaving  it  in  hot  ashes  all 
night.  This  method  makes  the  steel  very  soft  and  equalizes  the 
grain.  After  softening  turn  up  the  work,  taking  care  not  to  bend 
or  straighten  it,  should  it  have  cast,  as  it  probably  will  in  the  pro¬ 
cess  of  softening.  The  reason  for  this  is  that  if  the  steel  be  bent 
or  hammered  the  grain  will  be  closer  in  one  place  than  in  another, 
and  heat  has  a  great  tendency  to  bring  it  back  to  its  original  posi¬ 
tion.  The  next  thing  after  finishing  your  tool  is  to  harden  it  : 
first,  slightly  heat  it  over  a  gas  or  other  flame  and  rub  it  all  over 
with  a  mixture  of  castile  soap  and  lampblack.  This  is  to  prevent 
the  edges  from  being  burnt.  The  next  is  to  get  a  thick  iron  pipe 
2  inches  in  diameter  and  ^-inch  bore.  This  is  well  filled  up  with 
taps  or  dies  and  charcoal-dust,  the  ends  being  closed  with  clay  as 
before  ;  this  is  placed  in  the  furnace  and  occasionally  turned  until 
it  is  one  uniform  heat  of  cherry-red  or  on  the  outside  a  trifle  hotter. 
It  is  then  carefully  removed  from  the  fire,  one  end  of  the  clay  is 
knocked  off,  and  the  contents  are  allowed  to  drop  perpendicularly 
into  a  solution  of  water,  chloride  of  sodium  and  nitrate  of  iron  ; 
this  solution  is  kept  at  a  temperature  of  6o°  F.  The  articles  to  be 
hardened  should  remain  at  least  ^  hour  before  being  removed. 
This  method  of  hardening  maybe  summed  up  thus:  make  the 
steel  of  one  grain  throughout,  prevent  it  from  oxidizing  whilst  be¬ 
ing  heated,  allow  every  part  to  heat  at  the  same  time,  avoid  bend¬ 
ing  while  hot,  and,  lastly,  restore  if  possible  by  replacing  the  loss 
of  carbon  caused  by  heating. 

hnprovements  in  Tempering  and  Hardening  Steel  and  Iron. — 
Glycerin  is  used  in  tempering  steel,  cast-steel  or  cast-iron.  The 
specific  gravity  of  the  glycerin  may  be  varied  between  1.08  and 
1.26  at  590  F.  by  adding  water  according  to  the  composition  of  the 
steel.  The  quantity  of  glycerin  should  be  from  1  to  6  times  greater 
in  weight  than  the  weight  of  the  pieces  to  be  plunged  into  it,  and  its 
temperature  may  be  varied  from  590  to  3920  F.,  according  to  the 


ANNEALING,  HARDENING,  TEMPERING. 


147 


hardness  of  the  metal.  The  harder  the  steel  to  be  tempered  the 
higher  the  temperature  should  be,  and  for  a  mild  steel  a  low  tem¬ 
perature  should  be  used.  To  increase  the  quenching  power  of  the 
bath  various  salts  may  be  added  to  the  glycerin  solution.  Thus, 
when  a  hard  temper  is  wanted,  protosulphate  of  manganese  may  be 
added  in  quantity  varying  from  i  to  34  per  cent,  of  the  liquid  or 
from  to  4  per  cent,  of  potassium  sulphate.  For  a  softer  temper 
1  to  10  per  cent,  of  manganese  and  1  to  4  per  cent,  of  potassium 
chloride  may  be  added.  The  principal  advantages  to  be  derived 
from  these  methods  are:  1.  The  temperature  of  the  aqueous  solutions 
of  glycerin  may  be  varied  within  wide  limits,  the  boiling  point  of 
pure  glycerin  being  84. 2°  F.  2.  Owing  to  the  fact  that  solutions 
of  glycerin  in  water  dissolve  most  salts  that  are  soluble  in  water,  the 
quenching  properties  of  the  bath  may  readily  be  varied  by  dissolv¬ 
ing  such  salts  in  it  as  will  suit  the  kind  of  metal  to  be  tempered  and 
the  degree  of  temper  required. 

To  Temper  Brass. — Brass  not  hardened  by  mixture,  but  by  com¬ 
pression,  either  by  rolling,  hammering,  wire  drawing  or  any  other 
process  which  compresses  the  particles  of  metal,  can  be  tempered 
just  as  easily  and  in  the  same  manner  as  an  equal-sized  piece  of  hard¬ 
ened  steel  would  be  tempered,  viz. ,  by  heat.  By  placing  a  small  piece 
of  polished  steel  on  the  brass  object  to  be  tempered  and  applying 
the  heat  so  as  to  affect  equally  the  brass  and  steel,  the  color  of  the 
steel  will  indicate  the  temper  in  exact  proportion  to  every  shade  of 
color  of  the  steel. 

To  Temper  Magnets. — A  combined  process  for  tempering  and 
magnetizing  steel  bars  for  magnets  is  employed  by  M.  Ducoetet. 
He  uses  a  water-tight  vessel,  at  the  bottom  of  which  are  two  soft 
iron  pole  pieces ;  the  poles  of  a  powerful  electro-magnet  are  placed 
underneath  these.  The  vessel  is  partly  filled  with  water,  and  a 
layer  of  oil  is  above  this.  The  red-hot  bar  is  passed  through  these. 
Its  passage  first  through  the  oil  is  found  to  soften  the  steel  without 
depriving  it  of  its  power  of  being  magnetized. 


148 


THE  METAL  WORKER’S  II ANDY-BOOK. 


VI. 

BRONZING  AND  COLORING. 

Metals  are  bronzed  by  one  of  two  methods,  the  color  being 
produced  either  by  chemical  agents  or  by  the  application  of  bronze 
powders.  For  the  latter  purpose  there  are  found  in  trade  bronze 
powders  made  of  brass  in  an  impalpable  state  of  division  and  which 
present  the  most  varied  shades,  according  to  the  degree  of  oxida¬ 
tion  which  the  brass  undergoes  when  heated  in  contact  with  the 
air.  These  bronze  powders  are  applied  upon  metals  to  imitate 
bronze.  The  operation  is  entirely  mechanical.  After  the  object 
has  been  more  or  less  cleaned,  it  receives  a  thin  coating  of  a  fatty 
drying  varnish  which  is  allowed  to  become  nearly  dry.  A  good 
varnish  for  the  purpose  is  made  as  follows:  Boil  i  to  2  lbs.  of  lin¬ 
seed  oil  in  an  earthen  vessel  for  2  hours ;  then  remove  it  from  the 
fire  and  when  somewhat  cooled  off  add  gradually  1.23  ozs.  of  red 
lead.  If  on  adding  the  red  lead  a  red  scum  is  formed  upon  the 
surface  of  the  oil,  the  oil  is  too  hot  and  the  addition  of  red  lead  has 
to  be  interrupted  until  the  oil  is  cooler.  The  addition  of  red  lead 
is  succeeded  by  that  of  a  like  quantity  of  white  litharge.  The 
varnish  is  then  allowed  to  stand  in  the  sun  for  a  few  days  to  clarify 
and  finally  kept  for  use  in  a  glass  or  tin  vessel.  To  give  the  object 
a  gold  bronze,  ochre  is  triturated  with  the  varnish  and  some  blue  or 
black  mixed  with  it,  so  that  a  dirty  green  color  results.  Apply 
two  or  three  layers  of  this  color  to  the  surface  of  the  object  by 
means  of  a  soft  brush,  allowing  the  first  layer  to  dry  before  apply¬ 
ing  the  next.  The  last  coating,  however,  must  not  be  allowed  to 
become  entirely  dry.  The  bronze  powder  is  laid  upon  this  layer 
with  a  badger  brush  or  otherwise,  and  adheres  strongly.  After 
drying  and  dusting  off  the  superfluous  bronze  powder  with  a  stiff 
brush  the  whole  is  covered  with  a  coat  of  transparent  and  colorless 
varnish.  This  process  evidently  fills  up  the  details  and  is  suited 
only  to  large  pieces  which  are  imperfectly  finished. 

If  the  article  is  to  receive  a  silver  bronze,  rub  some  zinc  white 
and  lampblack  into  the  above-mentioned  varnish  so  that  a  sort  of 


BRONZING  AND  COLORING. 


149 


silver-gray  color  is  obtained.  Apply  2  or  3  coats  of  this  paint  to 
the  article  and  bronze  with  silver  bronze  before  the  last  coat  is  en¬ 
tirely  dry.  Very  beautiful  effects  can  in  this  manner  be  obtained 
by  the  use  of  various  ground-colors,  such  as  colcothar,  leaf-green, 
dark  gray  and  even  black.  In  bronzing  iron  it  is  very  advan¬ 
tageous  to  first  coat  it,  without  regard  to  the  succeeding  colors, 
with  red  oxide  of  iron,  rubbed  up  in  varnish,  and  then  apply  the 
actual  colors.  A  very  neat  bronzing  is  produced  with  a  paint  of 
graphite  and  varnish,  the  last  coat  of  which  is  dusted  over  before 
becoming  entirely  dry  with  aluminium  bronze  powder,  the  whole 
acquiring  thereby  the  appearance  of  polished  iron. 

Copper  Bronze  upon  iron  and  zinc  is  obtained  by  coating  the 
metal  with  a  brown  lacquer  or  varnish  and  dusting  copper-dust 
upon  it  in  the  manner  previously  described.  Copper-dust  may 
also  be  mixed  with  spirit  lacquer  and  applied  together  with  the 
lacquer. 

Red  Bronze  is  produced  by  the  application  of  red  bronze  lacquer 
or  red  bronze  powder  or  red  mosaic  gold.  For  bronzing  with  red 
bronze  lacquer  the  objects  must  be  clean  and  bright,  since  every 
stain  shows  through  the  lacquer.  For  bronzing  with  red  metallic 
bronze  the  object  is  first  coated  with  varnish  and  the  bronze  pow¬ 
der  laid  upon  it  with  a  velvet  rag  or  soft  brush. 

Green  Bronze  upon  tin,  zinc  and  lead  may  be  produced  by  the 
application  of  green  bronze  lacquer  of  a  dull  lustre  or  of  green 
varnish.  The  green  for  the  bronze  color  is  best  prepared  by  mix¬ 
ing  Frankfort  black  with  chrome  yellow. 

As  regards  bronzing  by  chemical  agents  it  is  not  necessary  to 
give  a  detailed  description  of  the  mode  of  application,  since  a 
large  number  of  receipts  and  their  use  for  bronzing  metals  and 
alloys  are  given  as  follows : 

French  Bronze. — A  new  bronze  upon  French  bronze  figures 
shows  all  shades  of  pale  or  clay-yellow  to  red-brown,  and  of  red  to 
dark  and  black-brown.  It  has  a  bronze-like  appearance,  and 
adheres  tightly  to  the  metal,  i.  e.,  is  chemically  combined  with  it. 
To  produce  such  colorations,  solutions  of  sulphur  combinations  of 
arsenic  and  antimony  have  been  successfully  used.  After  cleaning 


THE  METAL  WORKER’S  HANDY-BOOK. 


150 


and  pickling,  the  articles  must  be  subjected  to  a  thorough  washing 
with  water,  as  otherwise  every  trace  of  acid  left  behind  will  later 
on  in  drying  or  bronzing  penetrate  through  the  seams  and  produce 
indelible  stripes  and  stains.  Great  care  must  also  be  had  in  drying 
the  article.  For  applying  the  solutions  a  tuft  of  cotton,  or  a  soft, 
close  brush,  is  used.  The  operation  is  best  commenced  by  first 
applying  a  dilute  solution  of  ammonium  bisulphide  as  sparingly  as 
possible,  brushing  over  a  certain  limited  portion  of  the  figure  at 
one  time.  The  quicker  and  more  uniformly  this  is  done,  the  better 
and  more  beautiful  the  bronzing  will  be.  After  drying  the  sulphur 
separated  out  is  brushed  off,  and  a  solution  of  sulphide  of  arsenic 
in  ammonia  applied,  the  result  being  a  coloration  similar  to  mosaic 
gold.  The  oftener  this  solution  of  sulphide  of  arsenic  is  applied 
the  browner  the  color  becomes,  and  a  very  dark  brown  can  be 
finally  obtained  by  a  solution  of  sulphide  of  arsenic  in  ammonium 
bisulphide.  By  solutions  of  sulphide  of  antimony  in  ammonia  or 
ammonium  sulphide  the  coloration  becomes  reddish,  it  being 
p  issible  to  produce  the  most  delicate  rose  color  as  well  as  the 
deepest  dark  red.  By  rubbing  some  places  more  vigorously,  a  very 
fine  metallic  lustre  is  produced.  Ammonia  or  ammonium  sulphide 
redissolves  the  bronzing,  so  that  places  not  thoroughly  colored  can 
be  improved,  though  in  such  case  it  is  better  to  rub  off  the  entire 
figure  with  ammonium  sulphide.  In  the  same  manner  as  the  solu¬ 
tions  in  ammonia  or  ammonium  sulphide,  those  in  hydrate  or  sul¬ 
phide  of  potassium  or  sodium  can  also  be  used,  the  latter  being  in 
some  cases  even  more  advantageous.  By  slightly  pickling  the 
object  the  color  of  the  bronze  is  changed.  If  a  casting  of  bronze 
or  brass  is  left  too  long  in  the  pickle,  the  metal  becomes  coated 
with  a  greenish-gray  film,  which,  on  rubbing  with  a  piece  of  cloth, 
becomes  lustrous  and  adheres  firmly.  On  treating  with  the  above- 
mentioned  metallic  sulphides  this  coating  acquires  a  dull  yellow 
coloration.  The  number  of  such  agents  for  bronzing  can,  undoubt¬ 
edly,  be  still  further  augmented,  and  an  operator  having  some 
knowledge  of  chemistry  may  be  able  to  use  many  other  similar 
solutions  of  metallic  salts.  Heat  must  not  be  used. 

Blue  Bronze. — Prepare  a  sand-bath  as  large  as  the  article  to  be 


BRONZING  AND  COLORING. 


151 


bronzed.  Cleanse  the  article  from  all  grease  by  dipping  m  boiling 
potash  lye,  and  then  treat  it  with  white  vinegar.  Wipe  and  dry 
the  surface  thoroughly,  and  rub  it  with  a  linen  rag  moistened  with 
hydrochloric  acid.  Allow  the  coating  to  dry  for  a  quarter  of  an 
hour,  and  then  heat  the  article  on  the  sand-bath  until  it  has 
acquired  the  desired  color,  when  it  should  be  removed. 

Brown  Bronze. — Observe  the  same  directions  as  in  the  foregoing. 
The  blue  bronze  is  finally  rubbed  over  with  a  linen  rag  saturated 
with  olive  oil,  which  will  change  the  blue  color  into  brown. 

Bronzing  by  Dipping  in  Melted  Bronze. — This  process  is  similar 
to  tinning,  galvanizing,  etc.  The  bright  metal  is  dipped  in  bronze 
melted  under  a  cover  of  borax  in  an  iron  crucible,  and  moved  in  it 
until  it  has  acquired  the  temperature  of  the  melted  alloy  and  be¬ 
comes  uniformly  coated  with  it.  The  bronzed  article  is  then  taken 
out,  and  allowed  to  cool  upon  a  grate  by  moving  it  until  the  coat¬ 
ing  congeals.  Large  pieces  are  to  be  sufficiently  heated  before 
dipping,  in  order  to  prevent  the  melted  bronze  from  being  cooled 
off  too  much. 

Bronze  Liquid.-— Dissolve  sal-ammoniac,  i  oz.  ;  alum,  oz.  ; 
arsenic,  oz.,  in  strong  vinegar,  i  pint.  The  compound  is  im¬ 
mediately  fit  for  use,  and,  where  the  metal  is  good,  is  seldom  found 
to  fail. 

Cheap  Bronze. — Make  into  a  paste  with  oil,  and  melt  together 
verdigris,  16  ozs.  ;  flowers  of  zinc,  8  ozs;  borax  and  saltpetre,  of 
each  4  ozs. ;  corrosive  sublimate,  2  drachms.  This  bronze  is  used 
in  the  commoner  kinds  of  tea-boards,  etc. 

To  Bronze  Small  Brass  Articles. — Oxide  of  iron,  3  parts  ;  white 
arsenic,  3  parts;  hydrochloric  acid,  36  parts.  Clean  the  brass  well 
to  get  rid  of  grease,  etc.,  and  apply  with  a  brush  until  the  desired 
color  is  obtained.  Stop  the  process  by  oiling  well,  when  the  article 
may  be  varnished  or  lacquered. 

Bronzing  Process  Used  in  the  Paris  Mint. — Powder  and  mix  1  lb. 
each  of  verdigris  and  sal-ammoniac.  Take  a  quantity  of  this  mix¬ 
ture  as  large  as  a  hen’s  egg,  and  mix  into  a  dough  with  vinegar. 
Place  this  in  a  copper  pan  (not  tinned),  boil  in  about  5  pints  of 
water  for  20  minutes,  and  then  pour  off  the  water. 


152 


TIIE  METAL  WORKER’S  IIANDY-ROOK. 


For  bronzing,  pour  part  of  this  fluid  into  a  copper  pan  ;  place 
the  medals  separately  in  it  upon  pieces  of  wood  or  glass,  so  that 
they  do  not  touch  each  other,  or  come  in  contact  with  the  copper 
pan,  and  then  boil  them  in  the  liquid  for  a  quarter  of  an  hour. 

To  Bronze  Copper. — Dissolve  30  parts  of  carbonate  or  hydro¬ 
chlorate  of  ammonium  and  10  parts  each  of  common  salt,  cream  of 
tartar,  and  acetate  of  copper  in  100  parts  of  acetic  acid  of  moderate 
concentration,  or  in  200  parts  of  strong  vinegar,  and  add  a  little 
water.  When  an  intimate  mixture  has  been  obtained,  smear  the 
copper  object  with  it,  and  let  it  dry  at  the  ordinary  temperature 
for  24  to  48  hours.  At  the  end  of  that  time  the  object  will  be 
found  to  be  entirely  covered  with  verdigris  presenting  various  tints. 
Then  brush  the  whole,  and  especially  the  reliefs,  with  a  waxed  brush, 
and,  if  necessary,  set  off  the  high  reliefs  with  hematite  or  chrome 
yellow,  or  other  suitable  colors.  Light  touches  of  ammonia  give 
a  blue  color  to  the  green  portions,  and  carbonate  of  ammonium 
deepens  the  color  of  the  parts  on  which  it  is  laid. 

To  Bronze  Copper  Bluish-gray. — According  to  Dr.  Bottger,  a 
brightly  polished  sheet  of  copper  acquires  a  beautiful  bluish-gray 
color  by  applying  to  the  surface  a  fluid  obtained  by  the  warm 
digestion  of  cinnabar  with  a  solution  of  sodium  sulphide,  to  which 
some  caustic  lime  has  been  added. 

Green  Bronze  for  Brass. — I.  Mix  strong  vinegar,  80  parts; 
mineral  green,  1  ;  red  umber,  1  ;  sal-ammoniac,  1  ;  gum  arabic,  1; 
ferrous  sulphate  (green  vitriol),  1,  and  add  4  parts  of  Avignon 
berries  (fruits  of  Rhamnus  infeclorius').  The  articles  to  be  bronzed 
should  be  cleansed  with  dilute  nitric  acid,  then  rinsed  in  water  and 
the  fluid  applied  with  a  brush.  Should  the  color  not  be  dark 
enough  heat  the  article  until  it  cannot  be  held  in  the  hand  and 
then  give  it  a  coat  of  spirit  of  wine  mixed  with  a  little  lampblack. 
Finally  apply  a  coat  of  spirit  varnish. 

II.  Add  to  a  solution  of  8*4  drachms  of  copper  in  1  oz.  of 
strong  nitric  acid,  io}4  ozs.  of  vinegar,  3*4  drachms  of  sal-am¬ 
moniac  and  bY\  drachms  of  aqua  ammonia.  Put  the  liquid  in  a 
loosely-corked  bottle  and  allow  it  to  stand  in  a  warm  place  for  a 
few  days,  when  it  may  be  used.  After  applying  it  to  the  objects,  dry 


BRONZING  AND  COLORING. 


153 


them  by  exposure  to  heat,  and,  when  dry,  apply  a  coat  of  linseed 
oil  varnish,  which  is  also  dried  by  heat. 

To  Bronze  Articles  of  Copper  and  Brass. — Neutralize  20  parts 
by  weight  of  ammonia  with  vinegar  and  compound  the  solution  with 
10  parts  of  verdigris  and  6  of  sal-ammoniac.  Larger  articles  after 
being  freed  from  grease  and  other  impurities  are  brushed  with  the 
solution,  the  operation  being  repeated  until  the  desired  shade  of 
color  is  produced.  The  articles  are  dried  at  the  ordinary  tempera¬ 
ture  of  a  room.  Smaller  articles  are  dipped,  with  constant  stir¬ 
ring,  in  the  fluid  heated  nearly  to  the  boiling  point.  The  desired 
coloration  having  been  attained,  the  solution  is  poured  off  and  re¬ 
placed  by  hot  water,  the  rinsing  being  twice  repeated  with  stirring. 
The  articles  are  best  dried  in  saw-dust. 

Brown  Fire-proof  Bronze  upon  Copper  and  Brass. — Dissolve  1.12 
drachms  each  of  pulverized  verdigris  and  finely  powdered  sal-am¬ 
moniac  in  1  pint  of  water,  let  the  solution  stand  covered  3  or  4 
hours  and  then  add  1  y2  pints  of  water.  In  bronzing  hold  the  cop¬ 
per  article,  which  should  be  perfectly  clean,  over  a  coal  fire  and 
heat  to  a  uniform  heat  and  color.  Then  apply  the  solution  and 
dry  carefully.  Tinned  copper  must  not  be  heated  enough  to  melt 
the  tin.  By  thus  treating  copper  5  or  6  times  it  acquires  a  brassy 
color,  and  after  6  to  10  applications  a  beautiful  yellow  tint.  If  it 
is  desired  to  give  a  copper  article  a  color  shading  from  yellow  into 
brown  it  must  not  be  hot  when  the  mixture  is  applied;  for  light 
brown  the  operation  is  to  be  repeated  20  to  25  times.  When  the 
desired  color  has  been  obtained  place  the  article  at  once  in  clean 
water,  but  do  not  polish  or  dry  it  immediately  after  taking  it  out. 
In  fact,  the  greatest  care  is  here  required.  It  is  best  to  dry  the 
article  over  a  moderate  coal  fire,  when  the  bronze  will  become 
durable  and  fire-proof. 

Green  Bronzing. — The  repeated  alternate  applications  to  copper 
or  brass  of  dilute  acetic  acid  and  exposure  to  the  action  of  the  fumes 
of  ammonia  will  give  a  very  antique-looking  green  bronze ;  but  a 
quick  method  of  producing  a  similar  appearance  is  often  desirable. 
To  this  end  the  articles  may  be  immersed  in  a  solution  of  1  part 
of  perchloride  of  iron  in  2  parts  of  water.  The  shade  becomes 


154 


THE  METAL  WOllKER’S  HANDY-BOOK. 


darker  with  the  length  of  immersion.  Or,  the  articles  may  be 
boiled  in  a  strong  solution  of  nitrate  of  copper.  Or,  they  may  be 
immersed  in  a  solution  of  2  ozs.  of  nitrate  of  iron  and  2  ozs.  of 
hyposulphite  of  sodium  in  1  pint  of  water.  Washing,  drying  and 
burnishing  complete  the  process. 

Bronzing  of  Cast-iron. — To  give  cast-iron  the  appearance  of 
bronze  coat  the  polished  iron  with  a  thin  layer  of  linseed  oil  or 
linseed  oil  varnish  and  thoroughly  heat  it  in  the  air  to  bring  about 
the  oxidation  of  the  metal.  The  temperature  must  be  higher  or 
lower  according  to  whether  a  pale  yellow  or  dark  brown  coloration 
is  to  be  produced.  The  so-called  Tucker  bronze  is  obtained  by 
greasing  the  polished  iron  and  exposing  it  for  2  to  5  minutes  to  the 
action  of  vapors  produced  by  a  bath  composed  of  equal  parts  of 
concentrated  nitric  and  hydrochloric  acids,  then  coating  the  iron 
with  vaseline  and  heating  until  the  latter  commences  to  decompose. 

Gold  Bronze  of  Great  Lustre  on  Iron. — Dissolve  3  ozs.  of  finely 
powdered  shellac  in  1^  pints  of  spirit  of  wine.  Filter  the  varnish 
through  linen  and  triturate  a  sufficient  quantity  of  Dutch  gold  with 
the  filtrate  to  give  to  it  a  lustrous  appearance.  The  iron,  pre¬ 
viously  polished  and  heated,  is  brushed  over  with  vinegar  and  the 
color  applied  with  a  brush.  When  dry  the  article  may  be  coated 
with  copal  lacquer  to  which  some  amber  lacquer  has  been  added. 

To  Bronze  Cast-iron. — First  clean  and  smooth  the  surface  and 
then  coat  it  uniformly  with  a  layer  of  vegetable  oil,  for  instance  a 
poor  quality  of  olive  oil.  Then  heat,  without,  however,  raising  the 
temperature  to  the  burning  point  of  the  oil.  In  this  manner  the 
cast-iron  at  the  moment  the  decomposition  of  the  oil  takes  place 
absorbs  oxygen  and  a  brown  surface  of  oxide  is  formed  on  the  sur¬ 
face  which  adheres  very  firmly  and  acquires  a  good  polish,  so  that 
the  surface  of  the  cast-iron  assumes  a  bronze-like  appearance. 

Bronze-like  Surface  on  Iron  or  Steel. — A  very  fine  bronze-like 
surface,  and  one  that  will  prevent  rusting,  may  be  produced  on 
iron  or  steel  as  follows :  The  object  to  be  acted  upon  must  be 
cleansed,  so  as  to  take  off  all  oxidation  or  other  impurity.  It  is 
then  exposed  for  two  or  three  minutes  to  the  action  of  the  vapors 
of  a  heated  mixture  of  hydrochloric  acid  and  nitric  acid  in  equal 


BRONZING  AND  COLORING. 


155 


proportions,  at  a  temperature  ranging  from  550°  to  650°  F.  After 
the  objects  have  cooled,  they  are  to  be  rubbed  over  with  vaseline, 
and  again  heated  until  the  vaseline  begins  to  decompose.  This 
treatment  with  the  vaseline  has  to  be  repeated  once.  Should  a 
lighter  coloring  than  bronze  be  desired,  it  can  be  produced  by 
mixing  acetic  acid  with  the  other  acids.  In  using  the  above- 
named  chemicals  great  care  should  be  observed  in  handling  and 
preserving. 

To  Give  Ground  Steel  Objects  the  Appearance  of  Gold  or  Good 
Bronze. — First  remove  all  fatty  matter  and  dirt  from  the  steel 
object  by  washing  in  turpentine,  benzine,  or  petroleum,  then  heat 
and  apply  a  light  gold  varnish,  which,  when  dry,  is  coated  with  the 
clearest  and  best  copal  lacquer.  In  this  manner  an  elegant  gold 
color  of  various  shades  is  obtained,  according  to  the  more  reddish 
or  yellowish  color  of  the  varnish. 

To  Bronze  Tin. — Prepare  two  solutions :  one  of  1  part  ferrous 
sulphate  (green  vitriol),  1  part  cupric  sulphate  (blue  vitriol),  and 
20  parts  of  distilled  water;  and  the  other  of  4  parts  verdigris  and 
16  parts  vinegar.  Thoroughly  cleanse  the  article  by  means  of  a 
clean  brush  dipped  in  a  fine  earth  and  water,  and  after  thoroughly 
drying,  apply  to  both  sides  a  light  coat  of  the  first  solution  by 
means  of  a  brush.  After  drying,  the  article  presents  a  blackish 
appearance.  The  second  solution  is  then  applied  with  a  brush 
until  the  article  acquires  a  dark  copper-red  color.  It  is  now  allowed 
to  dry  one  hour,  and  then  polished  with  a  soft  brush  and  finely 
elutriated  bloodstone,  the  surface  being  frequently  breathed  upon 
so  as  to  make  the  bloodstone  adhere.  In  conclusion  it  is  polished 
with  the  brush  alone,  which  is  from  time  to  time  drawn  over  the 
palm  of  the  hand.  To  protect  the  bronze  against  moisture,  cover 
it  with  a  very  thin  layer  of  gold  lacquer. 

To  Bronze  Zinc. — The  zinc  to  be  bronzed  must  receive  an  electro¬ 
deposit  of  brass,  which  is  then  dipped  into  a  weak  solution  of  sul¬ 
phate  of  copper  for  a  red  tinge.  When  dry,  wet  with  a  rag  dipped 
into  hydrosulphate  of  ammonia,  or  a  solution  of  polysulphide  of 
potassium,  or  protochloride  of  copper  dissolved  in  hydrochloric 
acid.  After  another  drying,  the  surface  is  brushed  over  with  a 
mixture  of  peroxide  of  iron  and  plumbago,  according  to  the  tint 


156 


TTTE  METAL  WORKER'S  HANDY  BOOK. 


desired.  The  brush  may  be  slightly  wetted  with  essence  of  turpen¬ 
tine,  which  aids  the  adhesion  of  the  powder.  The  raised  portions 
are  strongly  rubbed  to  uncover  the  brass.  Afterwards  give  a  coat 
of  colorless  varnish.  According  to  another  method,  the  brassed  or 
coppered  article  is  pickled  with  dilute  nitric  acid,  and  then  coated 
with  a  paste  made  of  3  parts  of  peroxide  of  iron,  2  of  graphite,  and 
a  sufficient  quantity  of  spirits  of  wine.  After  24  hours  this  coating 
is  brushed  off,  and  a  dark-brown  bronze  will  appear.  A  bronze  of 
a  lighter  color  is  obtained  by  gently  rubbing  the  brassed  or  coppered 
zinc  with  a  soft  brush  dipped  in  a  solution  of  ozs.  of  sal- 
ammoniac,  and  3  ozs.  of  potassium  binoxalate  in  3*4  to  5^  pints 
of  vinegar. 

Silvered  Cast- Zinc  Articles  are  colored  partially  gray  and  partially 
black.  The  dark  colors  are  obtained  by  coating  with  a  solution  of 
liver  of  sulphur  and  also  by  rubbing  with  graphite. 

To  Bronze  Electrotypes — Green. — Steep  the  medal  or  figure  in  a 
strong  solution  of  common  salt,  or  sugar,  or  sal-ammoniac  for  a  few 
days,  wash  in  water,  and  allow  to  dry  slowly,  or  suspend  over  a 
vessel  containing  a  small  quantity  of  bleaching  powder,  and  cover 
over;  the  length  of  time  it  is  allowed  to  remain  will  determine  the 
depth  of  the  color. 

Brown. — Add  4  or  5  drops  of  nitric  acid  to  a  wineglassful  of 
water,  and  apply  the  mixture  to  the  object.  When  dry,  heat  the 
object  gradually  and  equally;  the  surface  will  be  darkened  in  pro¬ 
portion  to  the  heat  applied. 

Black. — Wash  the  surface  of  the  object  over  with  dilute  sulphide 
of  ammonia,  and  dry  at  a  gentle  heat;  finally,  polish  with  a  hard 
brush. 

To  Bronze  Medals. — The  most  simple  bronze  is  obtained  by 
applying  upon  the  cleansed  object  a  thin  paste  made  of  water  with 
equal  parts  of  plumbago  and  peroxide  of  iron,  with  a  certain  pro¬ 
portion  of  clay.  Then  heat  the  whole,  and  when  the  object  is 
quite  cold,  brush  in  every  direction  for  a  long  time  with  a  middling 
stiff  brush,  which  is  frequently  rubbed  upon  a  block  of  yellow  wax, 
and  afterwards  upon  the  mixture  of  plumbago  and  peroxide  of  iron. 
This  process  gives  a  very  bright  red  bronze,  suitable  for  medals 
kept  in  a  showcase. 


BRONZING  AND  COLORING. 


157 


A  similar  bronze  may  also  be  produced  by  dipping  the  article 
into  a  mixture  of  equal  parts  of  perchloride  and  nitrate  of  sesqui- 
oxide  of  iron,  and  heating  until  these  salts  are  quite  dry.  Then 
rub  with  the  waxed  brush  as  described. 

According  to  another  method,  the  object  is  cleansed  and  covered 
with  hydrosulphate  of  ammonia.  When  dry,  it  is  brushed  with 
peroxide  of  iron  and  plumbago,  and  afterwards  with  the  waxed 
brush.  If  the  object  impregnated  with  hydrosulphate  of  ammonia 
is  gently  heated  a  black  bronze  is  obtained,  which,  being  uncov¬ 
ered  at  certain  places,  produces  a  good  effect. 

Graham' s  Bronzing  Liquids.* — These  are  used  by  simple  immer¬ 
sions  and  have  a  wide  range  of  application,  as  will  be  seen  from 
the  following  three  tables : 


I.  For  Brass  {by  Simple  Immersion). 


Number.  [ 

J  Water.  j 

Nitrate  of  iron. 

Perchloride  of  iron. 

j  Permuriate  of  iron. 

Nitrate  of  copper. 

Tersulphide  of  ar¬ 
senic. 

Muriate  of  arsenic. 

i  Potash  solution  of 

sulphur. 

Pearl  ash  solution. 

Cyanide  of  potas¬ 
sium. 

Ferrocyanide  of  po¬ 
tassium  solution. 

Sulphocyamde  of  po¬ 
tassium. 

Hyposulphite  of  soda. 

Nitric  acid. 

Oxalic  acid. 

I 

pt. 

I 

dr. 

5 

dr. 

Pt. 

OZ. 

g>‘- 

OZ. 

dr. 

dr. 

OZ. 

pt. 

dr. 

dr. 

dr. 

OZ. 

Brown  and 

2 

1 

5 

every  shade 
to  black. 

tt  a 

3 

1 

l6 

l6 

.  . 

Brown  and 

4 

I 

l6 

I 

every  shade 
to  red. 

it  it 

s 

I 

I 

I 

Brownish-red. 

6 

3 

it  it 

7 

I 

4 

Dark  brown. 

8 

I 

30 

6 

Yellow  to  red. 

9 

I 

I 

Orange. 

10 

2 

1 

Olive-green. 

I  I 

I 

5 

2 

Slate. 

12 

I 

20 

Blue. 

13 

I 

I 

Steel-gray. 

14 

I 

2 

10 

Black. 

*  Brassfounder’s  Manual,  London,  1887. 


158 


Till]  METAL  WORKER’S  HANDY-BOOK. 


Liquid  No.  5  must  be  boiled  and  cooled.  No.  13  must  be  used 
at  1800  F.  or  over.  No.  6  is  slow  in  action,  sometimes  taking  an 
hour  to  give  good  results.  The  action  of  the  others  is  usually 
immediate. 


II.  For  Copper  {by  Simple  Immersion). 


Number. 

Water. 

Nitrate  of  iron. 

Sulphate  of  copper. 

Sulphide  of  anti¬ 
mony. 

Sulphur. 

Muriate  of  arsenic. 

Pearl  ash. 

I  Sulphocyanide  of  po- 

I  tassium. 

Hyposulphite  of  soda 

Hydrochloric  acid. 

Pt. 

dr. 

oz. 

dr. 

dr. 

dr. 

OZ. 

dr. 

OZ. 

dr. 

15 

I 

5 

Brown  and  every  shade  to  black. 

l6 

I 

5 

2 

Dark  brown-drab. 

17 

I 

I 

I 

2 

<<  it  it 

is 

I 

2 

I 

Bright  red. 

!9 

I 

I 

t 

Red  and  every  shade  to  black. 

20 

I 

I 

Steel-gray  at  1800  F. 

*  Made  to  the  consistency  of  cream. 


BRONZING  AND  COLORING. 


159 


Rockline' s  Method  of  Bronzing. — A  layer  of  jeweler’s  rouge 
moistened  with  water  is  applied  by  means  of  a  brush  to  the  article 
to  be  bronzed,  which  is  then  heated  to  a  red  heat.  By  this  process 
the  peroxide  of  iron  is  reduced  to  ferrous  oxide,  and  the  necessary 
quantity  of  oxygen  for  the  formation  of  a  suboxide  yielded  to  the 
copper.  The  coating  of  jeweler’s  rouge  is  then  removed  from  the 
article  to  be  bronzed  by  pouring  a  boiling  saturated  solution  of 
acetate  of  copper  over  it,  and  drying  with  tufts  of  cotton. 

Walker' s  Che?tiical  Bronze. — Boil  i  oz.  of  ammonium  carbonate 
and  a  like  quantity  of  blue  vitriol  in  i%  pints  of  vinegar  until  the 
latter  is  nearly  evaporated.  Then  add  pints  of  vinegar  in 
which  has  been  dissolved  drachm  of  oxalic  acid  and  a  like 
quantity  of  sal-ammoniac.  Place  the  mixture  over  the  fire  until 
it  commences  to  boil,  then  allow  it  to  cool,  filter  and  put  by  in 
well-closed  bottles. 

If  a  medal,  etc.,  is  to  be  bronzed,  it  is  first  thoroughly  cleansed, 
then  heated  and  the  liquid  applied  with  a  badger’s  hair  brush.  In 
a  short  time  boiling  water  is  poured  over  the  medal  and,  when  dry, 
it  is  rubbed  with  a  cotton  rag  dipped  in  oil  and  then  with  dry 
cotton. 

Bronze  Powders. — In  metal-leaf  (Dutch  gold)  factories  the 
waste  resulting  in  rolling  and  hammering  is  used  in  the  preparation 
of  bronze  powder.  According  to  the  old  method  the  waste  was 
rubbed  with  a  honey  or  gum  solution  upon  a  stone  until  a  mass 
consisting  of  fine  powder  combined  to  a  dough  by  the  honey  or 
gum  solution  was  formed.  This  dough  was  thrown  into  water,  and 
after  the  solution  of  the  cementing  substance  the  metallic  powder 
was  dried,  and  subjected  to  oxidation  by  mixing  it  with  a  little  fat 
and  heating  it  in  a  pan  over  an  open  fire  until  the  desired  shade  of 
color  was  obtained.  At  the  present  time  this  laborious  and  time- 
consuming  method  has  been  much  shortened  by  the  use  of  suitable 
machines,  and  of  alloys  prepared  by  melting  together  the  metals  in 
suitable  proportions  for  powders  which  do  not  require  to  be  colored 
by  oxidation.  These  alloys  are  beaten  out  into  thin  leaves  by 
hammers  driven  by  steam.  The  leaves  are  then  converted  into 
powder  by  forcing  them  through  the  meshes  of  a  fine  iron-wire 


160 


THE  METAL  WORKER’S  HANDY-BOOK. 


sieve  with  the  assistance  of  a  scratch-brush.  This  rubbing  through 
the  sieve  is  effected  with  a  simultaneous  admission  of  oil,  and  the 
mass  running  off  from  the  sieve  is  brought  into  a  grinding 
machine  of  peculiar  construction — a  steel  plate  covered  with  fine 
blunt-pointed  needles  revolving  over  another  steel  plate.  In  this 
machine  the  mass  is  reduced  to  a  very  fine  powder  mixed,  however, 
with  oil.  The  powder  is  first  brought  into  water  where  the  greater 
portion  of  the  oil  separates  on  the  surface.  The  metallic  mass 
lying  on  the  bottom  of  the  vessel  is  then  subjected  to  a  strong 
pressure,  which  removes  nearly  all  the  oil,  the  small  quantity  re¬ 
maining  exerting  no  injurious  influence,  but  being  rather  beneficial, 
as  it  causes  the  powder  to  adhere  with  greater  tenacity  to  the 
articles  to  which  it  is  applied. 

In  the  following  table  the  composition  of  the  alloys  for  some  colors 
is  given  : 


Color. 

Parts. 

Copper. 

Zinc. 

Iron. 

Yellow . 

82.33 

16.69 

0.16 

Pale  green .  . 

8432 

15.02 

0.63 

Lemon . 

84  50 

15  30 

0.07 

Copper-red . 

99.90 

Orange . 

98.93 

0-7  3 

Pale  yellow . 

90.00 

9.60 

Crimson  . . . 

98.22 

0.50 

0.56 

English  Brotize  Powders. — The  better  qualities  of  English  bronze 
powders  consist  of  copper,  83  parts  ;  silver,  4.5  ;  tin,  8 ;  oil,  4.5  ; 
and  the  poorer  qualities  of  copper,  64.8  parts;  silver,  4.3;  tin, 
8.7  ;  zinc,  12.9  ;  and  oil,  3. 

Brocade  Bronze  Powder. — The  variety  of  bronze  powder  known 
under  this  name  consists  of  coarser  pieces  prepared  from  the  waste 
of  metal-leaf  factories,  by  comminuting  it  by  means  of  a  stamping 
mill  and  separating  the  pieces  of  unequal  size  formed  first  by 


BRONZING  AND  COLORING. 


161 


passing  through  a  sieve  and  finally  by  a  current  of  air.  A  certain 
kind  of  brocade  consists,  however,  not  of  metallic  alloy,  but 
simply  of  mica  rubbed  to  a  fine  powder. 

Copper  Bronze  Powder  may  be  obtained  by  dissolving  copper  in 
nitric  acid,  diluting  the  solution  with  water,  and  then  putting  into 
it  some  small  pieces  of  brightly  scoured  iron  when  the  copper  will 
be  precipitated  in  a  metallic  state.  The  fluid  is  then  poured  off, 
the  powder  carefully  washed,  dried  and  rubbed  to  heighten  its 
lustre. 

Genuine  Gold  Bronze. — Leaf  gold  is  ground  with  honey  upon  a 
stone  until  the  leaves  are  broken  up  and  minutely  divided.  The 
mixture  is  then  removed  from  the  stone  by  a  spatula  and  stirred  up 
in  a  basin  of  water,  whereby  the  honey  is  melted  and  the  gold  set 
free ;  the  basin  is  then  left  undisturbed  until  the  gold  subsides ; 
the  water  is  poured  off  and  fresh  quantities  added  until  the  honey 
is  entirely  washed  away.  The  gold  is  finally  collected  on  filtering 
paper  and  dried  for  use.  Gold  bronze  occurs  in  various  shades  or 
colors,  red,  reddish,  pale  or  dark  yellow,  as  well  as  greenish,  the 
color  depending  on  the  varying  content  of  gold  or  the  different 
mixture  of  gold  with  silver  and  copper.  By  boiling  with  various 
salt  solutions  or  acidulated  masses  various  tones  may  also  be  im¬ 
parted  to  gold  bronze.  It  acquires  a  vivid  yellow  color  by  boiling 
in  water  containing  nitric,  sulphuric  or  hydrochloric  acid,  a  red¬ 
dish  color  by  boiling  in  a  solution  of  crystallized  verdigris  or  blue 
vitriol  in  water,  while  other  shades  are  obtained  by  boiling  in  solu¬ 
tions  of  common  salt,  tartar,  green  vitriol  or  saltpetre  in  water. 

Metallic  gold  powder  is  also  obtained  by  dissolving  pure  gold  in 
aqua  regia  and  precipitating  it  again  by  an  electro-positive  metal, 
such  as  iron  or  zinc,  which  in  the  form  of  rods  is  placed  in  the 
fluid.  The  gold  is  thereby  entirely  separated.  The  rods  used  for 
precipitation  must  be  scoured  perfectly  clean  and  bright.  The  lustre 
of  the  gold  bronze  may  be  heightened  by  rubbing  after  drying. 

Aurum  Musivum  (. Mosaic  Gold). — This  is  chiefly  used  for  bronz¬ 
ing  copper  and  brass,  plaster  of  paris  figures,  etc.  It  is  mixed  with  6 
parts  of  bone-ash  and  rubbed  moist  on  the  object.  It  is  best  pre¬ 
pared  as  follows  :  Melt  2  parts  of  tin  in  a  crucible,  and  add  with 
11 


162 


THE  METAL  WORKER’S  HANDY-BOOK. 


constant  stirring,  i  part  of  mercury  previously  heated  so  far  that  it  just 
commences  to  volatilize.  When  cool  grind  the  amalgam  to  a  fine 
powder  and  intimately  mix  it  with  i  part  of  sal-ammoniac  and  i  of 
flowers  of  sulphur,  and  place  the  mixture  in  a  closed  glass  flask  or 
retort  in  a  sand-bath.  Now  heat  sufficiently  for  the  vapors  to 
escape,  which  deposit  on  the  upper  part  of  the  vessel.  Sublima¬ 
tion  being  finished  take  the  vessel  from  the  sand-bath  and  allow  it 
to  cool.  The  upper  portion  of  the  contents  forms  the  bronze, 
which  is  of  a  vivid  gold-color,  while  the  lower  portion  consists  of 
sal-ammoniac  and  cinnabar.  On  account  of  the  injurious  vapors  a 
good  draught  should  be  provided  for  or  the  operation  carried  on  in 
the  open  air. 

Brownish  Gold  Bronze  Powders  are  obtained  by  exposing  to  the 
air  and  repeatedly  moistening  with  a  little  water  fine,  clean  iron- 
filings,  then  boiling  several  times,  and  finally  placing  the  mass  in 
the  sun  or  near  a  stove.  A  deep  rust-brown  powder  is  thus 
formed,  which  becomes  still  more  intensely  red  by  repeatedly 
adding  a  little  nitric  acid  during  the  last  boiling.  The  powder  is 
freed  from  metallic  iron-filings  by  washing,  and  dried.  By  mixing 
this  powder  with  imitation  gold  bronze  or  mosaic  gold,  bronze 
powders  of  the  most  varying  shades  may  be  made. 

Genuine  Silver  Bronze  Powder  is  obtained  by  grinding  waste  of 
silver-leaf  in  the  same  manner  as  given  for  gold  bronze,  or  by  dis¬ 
solving  silver  in  nitric  acid,  diluting  the  solution  with  water  and 
precipitating  the  silver  as  metallic  powder  by  placing  a  piece  of 
brightly  scoured  copper-sheet  in  the  solution. 

Imitation  Silver  Bronze  Powder  is  obtained  from  the  waste  of 
imitation  silver-leaf,  which  is  rubbed  fine,  washed  and  dried.  To 
heighten  the  lustre  of  the  powder  it  is  again  rubbed  when  dry. 

Argentum  Musivum. — This  is  an  amalgam  of  equal  parts  of 
mercury,  bismuth  and  tin.  It  may  also  be  prepared  as  follows: 
Melt  50  parts  of  good  tin  in  a  crucible,  and  when  liquid  add  50 
parts  of  bismuth,  stirring  constantly  with  an  iron  wire  until  the 
bismuth  is  liquid.  Then  remove  the  crucible  from  the  fire  and  stir 
in,  while  the  contents  are  still  liquid,  25  parts  of  mercury  and  mix 
the  mass  until  it  can  be  ground  upon  a  stone. 


BRONZING  AND  COLORING. 


163 


Iron  Black. — A  bronze-color  occurring  in  commerce  under  the 
name  of  “iron  black,”  and  which  imparts  to  the  articles  treated 
with  it  the  appearance  of  bright  steel,  is  finely  divided  antimony, 
and  may  be  obtained  by  precipitating  a  solution  of  antimony  salt 
with  metallic  zinc. 

Metallochromy. — Of  importance  for  the  metal  industry  are  the 
beautiful  rainbow-colors  which  may  be  produced  by  decomposing 
upon  polished  metallic  surfaces  certain  solutions  of  metallic 
salts  by  means  of  the  galvanic  current.  The  metallic  surface 
to  be  colored  is  connected  to  the  poles  of  a  powerful  galvanic 
battery,  and  at  a  distance  of  about  y2  line  is  placed  the  point 
of  a  wire  connected  to  the  second  pole.  The  colors  produced 
resist  more  or  less  friction,  are  surprisingly  brightened  by  heat, 
and  can  stand  a  considerable  degree  of  it.  To  color  articles 
of  brass  the  following  method  is  frequently  used:  Prepare  a 
solution  of  7  ozs.  of  caustic  potash  or  of  6  ozs.  of  caustic  soda 
in  2  quarts  of  distilled  water  and  boil  it  together  with  A,y2  ozs.  of 
elutriated  litharge  in  a  porcelain  dish  for  y2  hour,  constantly 
replacing  the  water  lost  by  evaporation.  Allow  the  fluid  to  settle, 
then  pour  off  the  supernatant  clear  liquid  and  preserve  it  for  use. 
For  coloring  the  fluid  is  placed  in  a  porous  clay  cell  surrounded  in 
a  glass  vessel  by  a  fluid  consisting  of  i  part  of  nitric  acid  and  20 
parts  of  water.  In  this  dilute  acid  is  placed  a  platinum  plate  and 
in  the  fluid  in  the  clay  cell  the  object  to  be  colored,  the  latter 
being  connected  with  the  negative  pole  of  a  battery.  The  colors 
appear  and  change  very  rapidly.  For  coloring  metals  by  the 
galvanic  current  Matthey  uses  chiefly  lead  suboxide  and  ferric 
oxide.  Preparation  of  the  lead  solution  :  Boil  4 y2  ozs.  of  litharge,  or 
better,  massicot  prepared  by  glowing  for  10  minutes,  red  lead 
with  a  solution  of  16  ozs.  of  caustic  potash  in  1  quart  of  distilled 
water.  When  cool  pour  off  the  clear  fluid  from  the  undissolved 
lead  oxide  and  dilute  it  with  distilled  water  until  it  shows  24  or 
250  Be'.  Preserve  the  fluid  in  a  well-stoppered  bottle;  when  used 
in  the  course  of  time  it  deposits  potassium  carbonate.  It  is  then 
boiled  with  caustic  lime,  allowed  to  settle,  and  the  clear  fluid  is 
again  used.  From  time  to  time  it  must  be  again  boiled  with  lead 


164 


THE  METAL  WORKER’S  HANDY-BOOK. 


oxide.  Preparation  of  the  iron  solution :  This  fluid  may  be  frequently 
used  and  in  many  cases  is  indispensable,  it  giving  shades  which 
cannot  be  obtained  with  lead  solution.  It  consists  of  an  aqueous 
solution  of  ferrous  sulphate  and  ammonia,  and  is  prepared  by 
mixing  a  freshly  prepared  solution  of  green  vitriol  in  distilled 
water  free  from  air  with  some  dilute  sulphuric  acid  and  with  liquid 
ammonia  until  the  precipitate  at  first  formed  redissolves.  The 
solution  thus  prepared  must  be  immediately  used,  it  decomposing 
on  exposure  to  the  air,  ferric  hydrate  being  separated.  The  colors 
produced  with  this  fluid  are  less  durable  than  those  obtained  with 
lead  solution,  but  they  are  brighter  and  adhere  as  firmly  as  the  blue 
produced  on  steel  by  heating.  Preparation  of  the  objects  to  be 
colored :  Galvanic  coloration  should  be  preferably  produced  upon 
a  non-oxidizable  layer  of  metal.  Gold  or  a  gilt  surface,  or 
platinum  is  especially  suitable  as  a  base  for  the  lead  oxide 
separating  from  the  lead  solution.  Upon  platinum  it  produces  a 
beautiful  blue  and  upon  gold,  green.  The  coloration  of  silver  is 
not  so  good  as  that  of  other  metals  because  its  surface  becomes 
immediately  dead  by  oxidation.  The  better  the  article  to  be 
colored  is  polished,  the  brighter  the  colors  obtained  ;  a  surface 
polished  with  the  burnisher  becomes  more  beautiful  than  one 
simply  polished  with  ferric  oxide.  Before  coloring  each  article 
should  be  carefully  cleansed  with  an  aqueous,  or,  still  better, 
alcoholic  solution  of  potash.  After  cleansing  the  articles  must 
not  be  touched  with  the  fingers  or  a  cloth.  As  a  galvanic  ap¬ 
paratus  the  inventor  employs  a  small  constant  battery  with  two 
elements. 

Weil' s  Process  of  Producing  Iridescent  Copper  Precipitates  on 
Iron. — The  bath  to  be  used  is  obtained  by  precipitating  35  parts  of 
sulphate  of  copper,  or  an  equivalent  quantity  of  another  copper 
salt  by  an  alkali.  The  precipitated  hydrated  oxide  of  copper  is 
then  added  to  a  solution  of  150  parts  of  potassium  tartrate,  and 
this  mixture  to  1000  parts  of  water.  By  now  adding  60  parts  of  70 
per  cent,  caustic  soda  a  clear  copper  solution  is  obtained.  The 
object  to  be  coppered  is  thoroughly  treated  with  a  scratch-brush  in 
a  bath  of  a  solution  of  potassium  tartrate,  then  secured  as  cathode 


BRONZING  AND  COLORING. 


165 


to  the  wire  of  the  negative  pole  and  immersed  in  the  bath.  The 
bath  gives  a  well-adhering  coating  of  copper,  and  can  be  continually 
used  by  replacing  the  consumed  copper  by  the  addition  of  hydrated 
oxide  of  copper  ;  the  quantity  of  copper  thus  added  must,  however, 
not  be  so  large  as  to  exceed  the  original  proportion  of  hydrated 
oxide  of  copper  to  potassium  tartrate.  If  the  latter  be  the  case,  an 
iridescent  film  of  a  brass  to  bronze-color  appearance,  or  of  a  red, 
blue,  and  green  color,  according  to  the  strength  of  the  current,  the 
duration  of  the  action,  and  the  proportional  quantity  of  hydrated 
oxide  of  copper,  is  formed.  These  colors  are  very  suitable  for 
industrial  purposes,  and  their  effect  may  be  increased  by  covering 
certain  portions  of  the  article  so  as  to  retain  the  original  copper  or 
iron  base. 

Approved  Coatings  for  Metals. — i.  Black  or  Colored  Coat.  Dis¬ 
solve  flowers  of  sulphur,  about  5  to  10  per  cent.,  in  hot  oil  of  tur¬ 
pentine,  and  gradually  add  to  the  solution,  with  constant  stirring, 
a  corresponding  quantity  of  linseed-oil  varnish.  A  black  paint  is 
obtained  by  the  addition  of  solution  of  asphalt,  and  any  other  color 
desired,  by  mixing  with  non-metallic  coloring  substances.  This 
paint  protects  the  metal  coated  with  it  by  superficially  converting 
it  into  sulphur  combinations. 

2.  Golden  Yellow  to  Brown  Coat. — Place  a  sufficient  quantity  of 
vulcanized  rubber  in  small  pieces  in  an  earthen  pot,  provided  with 
a  well-fitting  lid,  upon  glowing  coals  for  5  minutes  ;  do  not  remove 
the  lid,  as  the  vapors  developed  are  very  inflammable.  Pour  the 
melted  mass  into  a  tin  dish  to  cool ;  for  the  easier  removal  of  the 
cooled  mass,  it  is  advisable  to  slightly  grease  the  tin  dish.  Next 
break  up  the  mass  into  small  pieces,  put  them  in  a  capacious  bottle, 
pour  benzine  and  rectified  oil  of  turpentine  upon  them,  and  shake 
frequently  until  all  is  dissolved  except  a  slight  sediment.  The 
fluid  poured  off  from  the  sediment  is  an  excellent  quickly  drying 
varnish,  which  adheres  firmly  to  metals,  and  can  also  be  recom¬ 
mended  for  electrical  apparatus. 

3.  Black  Coat. — To  obtain  this,  it  is  first  necessary  to  procure 
very  good  and  pure  platinum  chloride.  It  is  best  prepared  by  dis¬ 
solving  platinum  in  aqua  regia  (3  parts  hydrochloric  acid  and  1  part 


1G6 


TnE  METAL  WORKER’S  HANDY-BOOK. 


nitric  acid).  By  evaporating  the  solution,  the  desired  platinum 
chloride  is  obtained  in  the  form  of  crystals,  which  are  dissolved  in 
water.  A  very  beautiful  and  durable  black  color  is  produced  upon 
the  articles  by  dipping  them  into  the  solution,  or  coating  them  with 
a  sponge  moistened  with  the  solution.  The  same  effect  is  also  pro¬ 
duced  by  allowing  the  crystals  to  deliquesce  in  the  air,  and  vigor¬ 
ously  rubbing  the  metal  with  the  moist  powder  by  means  of  a  piece 
of  leather,  or  smaller  articles  with  the  thumb  or  palm  of  the  hand. 
To  obtain  good  results,  the  articles  to  be  blackened  must  be  given  a 
pure  metallic  surface  by  turning  or  in  some  other  manner,  be  carefully 
polished,  and  especially  freed  from  adhering  grease  by  rubbing  with 
Vienna  lime,  jeweler’s  rouge,  etc.  Various  shades  of  color  can  be 
produced.  The  articles  treated  as  above  described  are  dead  black  ; 
a  lustrous  black  color  is  obtained  by  polishing  with  a  soft  piece  of 
leather  moistened  with  oil,  and  a  lustrous  gray-black  color  by¬ 
polishing  with  the  burnisher  or  burnishing  stone.  The  color, 
especially  when  polished,  is  very  durable,  since  platinum  is  not 
changed  by  the  action  of  the  air.  A  black  color  may  also  be 
obtained  by  the  following  process  :  First  brush  the  article  over 
with  nitric  acid,  and,  after  drying  by  heating,  brush  vigorously  to 
obtain  uniformity.  Then  lay  the  article  over  a  vessel  containing 
solution  of  liver  of  sulphur,  and  expose  it  to  the  action  of  the 
developing  sulphuretted  hydrogen. 

4.  Beautiful  Steel  Gray. — This  coating  is  obtained  by  the  use  of 
a  mixture  prepared  as  follows:  Triturate  3.85  grains  of  lamp¬ 
black  with  3  to  4  drops  of  gold-size  oil  in  a  dish  to  a  homogeneous 
coherent  mass,  and  carefully  dilute  the  latter  with  24  drops  of  oil 
of  turpentine.  This  mixture  is  especially  suitable  for  optical  instru¬ 
ments.  Apply  a  very  thin  and  uniform  coating  to  the  articles  by 
means  of  a  fine  brush,  and  allow  to  dry  thoroughly. 

New  Process  of  Producing  a  Gold-colored  Coating  upon  Small 
Metallic  Articles. — The  articles  of  tombac  or  brass  or  similar  sheet 
ornamented  with  sunk  ornamentations,  inscriptions,  names,  etc., 
are  first  pickled  in  the  ordinary  manner,  then  silvered  in  an  or¬ 
dinary  silver-bath  and  finally  brought  into  a  bath  consisting  of  6 
lbs.  of  distilled  water,  1  oz.  sodium  hyposulphite  and  0.35  oz.  of 


BRONZING  AND  COLORING. 


167 


sugar  of  lead.  Dissolve  the  sugar  of  lead  by  itself  in  water  and 
add  the  saturated  solution  to  the  solution  of  the  sodium  sulphite  in 
the  water.  Dip  the  silvered  articles  in  this  bath  previously  heated 
to  from  140°  to  167°  F.  until  they  have  acquired  the  correct  gold- 
color,  which  will  require  2  or  3  minutes,  according  to  the  tempera¬ 
ture  of  the  bath.  Articles  with  holes  or  eyes  may  be  strung  upon 
wires  and  suspended  in  the  bath;  otherwise  immersion  suffices. 
When  taken  from  the  bath  the  articles  are  rinsed  in  clean  cold 
water,  rubbed  with  dry  saw-dust  and  dried. 

Colored  Coatings  for  Metals. — These  maybe  obtained  by  forming 
on  the  surfaces  of  the  metals  a  coating  of  a  thin  film  of  a  sulphide, 
but  the  process  requires  in  its  application  considerable  experience. 
The  thorough  cleaning  of  the  articles  from  grease  by  immersion  in 
boiling  potash  lye  and  rinsing  in  water  is  absolutely  necessary  to  suc¬ 
cess.  The  process  is  as  follows :  In  a  quart  of  pure  water  dissolve 
1  oz.  of  hyposulphite  of  sodium.  Stir  into  this  another  solution 
made  by  dissolving  1  oz.  of  acetate  of  lead  in  a  pint  of  water. 

For  use  heat  the  solution  in  a  glass  or  earthenware  pan  to  about 
1 950  F.  and  immerse  in  it  the  metal  to  be  colored.  The  coat¬ 
ing  is  one  of  lead  sulphide,  and  its  depth  of  color  will  depend 
upon  the  time  the  metal  is  immersed.  In  a  few  minutes  brass  ar¬ 
ticles  of  small  size  may  be  coated  with  any  color  varying  from 
golden-yellow  to  the  tint  of  clean  copper  or  red  gold  to  carmine, 
down  to  dark  red ;  from  light  analine-blue  to  bluish-white,  then  to 
reddish-white  or  brown.  Steel  and  iron  articles  may  also  be  treated 
and  given  a  fine  blue  color  without  the  aid  of  such  great  heat  as  is 
necessary  in  “bluing”  or  oxidizing.  Copper  articles  do  not,  of 
course,  show  the  lighter  tints.  If  the  cleaning  is  well  done  the 
adhesion  will  be  perfect,  so  perfect,  indeed,  that  the  burnisher  may 
be  used  with  impunity  ;  but  it  is  not  prudent  to  use  the  scratch¬ 
brush.  Instead  of  burnishing,  however,  the  surface  may  be  fin¬ 
ished  by  a  soft  and  smooth  buff,  which  will  impart  a  lasting  polish. 

The  solution  will  not  keep  long  in  the  heated  state,  as  it  deposits 
its  sulphide  upon  the  bottom  of  the  vessel  if  no  metals  are  present. 

A  beautiful  red  and  green  coloring  can  be  given  to  brass  articles 
by  omitting  the  lead  and  using  in  its  stead  an  equal  weight  of  sul- 


168 


TIIE  METAL  WORKER’S  II ANDY-BOOK. 


phuric  acid.  If  the  immersion  continues  the  red  changes  to  a 
fine,  brilliant  green,  and  then  to  green  and  brown,  with, a  splendid 
iris  glitter.  This  coating  is  very  durable  and  may  be  especially 
recommended. 

Coloring  of  Copper. — All  shades  from  pale  copper  color  to  dark 
chestnut-brown  may  be  produced  by  a  superficial  oxidation  of  the 
copper.  Uniform  heating  over  a  spirit  flame  suffices  for  small  ar¬ 
ticles,  while  with  larger  objects  a  more  uniform  result  is  attained 
by  heating  them  in  oxidizing  fluids  or  coating  with  an  oxidizing 
paste.  Excellent  results  are  obtained  with  a  paste  prepared,  ac¬ 
cording  to  the  darker  or  lighter  shade  desired,  from  2  parts  ferric 
oxide  and  1  part  graphite,  or  1  part  ferric  oxide  and  1  part  graphite, 
and  water  or  alcohol.  This  paste  is  uniformly  applied  with  a  brush 
and  the  article  thus  treated  put  in  a  warm  place.  The  darker  the 
color  desired  the  higher  the  temperature  must  be  and  the  longer  it 
must  act  upon  the  object.  When  the  heat  has  sufficiently  acted 
upon  the  article  the  dried  powder  is  removed  by  brushing  with  a 
soft  brush,  and  the  manipulation  repeated  in  case  the  shade  is  not 
sufficiently  dark.  The  article  is  finally  rubbed  with  a  soft  linen 
rag  moistened  with  alcohol,  or  brushed  with  a  soft  brush  and  a  few 
drops  of  alcohol  until  it  is  completely  dry,  and  then  brushed  over 
with  a  brush  previously  rubbed  upon  pure  wax.  The  more  or  less 
dark  shade  produced  in  this  manner  is  very  warm  and  resists  the 
action  of  the  air. 

Brown  Color  upon  Copper  is  obtained  by  the  application  to  the 
thoroughly  cleansed  surface  of  the  object  of  a  paste  of  3  parts  of 
verdigris,  3  of  ferric  oxide,  1  of  sal-ammoniac  and  vinegar,  and 
heating  until  the  applied  mixture  turns  black ;  the  object  is  then 
washed  and  dried.  By  the  addition  of  some  cupric  sulphate  (blue 
vitriol)  the  color  may  be  darkened  to  chestnut-brown. 

A  brown  color  is  further  obtained  by  brushing  to  dryness  with  a 
hot  solution  of  1  part  of  potassium  nitrate,  1  of  common  salt,  2  of 
ammonium  chloride  and  1  of  liquid  ammonia  in  95  parts  of 
vinegar. 

Red-brown  Color  on  Copper. — Make  a  paste  of  2  parts  of  verdi¬ 
gris,  2  of  cinnabar,  5  of  sal-ammoniac  and  5  of  alum  with  sufficient 


BRONZING  AND  COLORING. 


169 


vinegar.  Apply  this  paste  to  the  article  and  after  heating  over  a 
coal  fire  wash  and  repeat  the  process. 

To  Color  Copper  Blue-black. — Dip  the  article  in  a  hot  solution  of 
ix%  drachms  of  liver  of  sulphur  in  i  quart  of  water,  moving  it 
constantly.  Blue-gray  shades  are  obtained  with  more  dilute  solu¬ 
tions.  It  is  difficult  to  give  definite  directions  as  to  the  length  of 
time  the  solution  should  be  allowed  to  act,  since  this  depends  con¬ 
siderably  on  its  temperature  and  concentration.  With  some  ex¬ 
perience  the  correct  treatment  will,  however,  soon  be  learned. 

Cuivre  fume  is  prepared  by  coloring  the  copper  or  coppered  ob¬ 
jects  blue-black  with  a  solution  of  liver  of  sulphur,  then  rinsing 
them  and  finally  scratch-brushing,  whereby  the  shade  becomes 
lighter.  From  raised  portions,  which  are  not  to  be  dark,  but  show 
the  color  of  copper,  the  coloration  is  removed  by  polishing  upon  a 
felt  disk. 

Steel-gray  upon  Copper. — To  produce  a  steel-gray  color  upon 
copper,  dip  the  clean  and  pickled  articles  in  a  heated  solution  of 
chloride  of  antimony  in  hydrochloric  acid.  By  using  a  strong 
galvanic  current  the  articles  may  also  be  coated  with  a  steel-gray 
precipitate  of  arsenic  in  a  heated  arsenic-bath. 

To  Color  Copper  Dark  Steel-gray . — For  this  purpose  a  pickle 
consisting  of  i  quart  of  hydrochloric  acid,  0.125  quart  of  nitric 
acid,  1  y2  oz.  of  arsenious  acid  and  a  like  quantity  of  iron  filings 
is  recommended. 

Various  Colors  upon  Massive  Copper. — First  draw  the  article 
through  a  pickle  composed  of  sulphuric  acid,  60  parts ;  hydro¬ 
chloric  acid,  24.5,  and  lampblack,  15.5;  or,  of  nitric  acid,  100 
parts;  hydrochloric,  1^  ;  and  lampblack,  Then  dissolve  in  a 
quart  of  water  4.58  ozs.  of  sodium  hyposulphite,  and  in  another  quart 
of  water  14.11  drachms  of  cupric  sulphate  (blue  vitriol),  5.64 
drachms  of  crystallized  verdigris  and  7.75  grains  of  sodium  ar¬ 
senate.  Mix  equal  volumes  of  the  two  solutions,  but  no  more 
than  is  actually  necessary  for  the  work  in  hand,  and  heat  to  167° 
to  176°  F.  By  dipping  articles  of  copper,  brass  or  nickel  in  the 
hot  solution  they  become  immediately  colored  with  the  colors 
mentioned  below,  one  color  passing  within  a  few  seconds  into  the 


170 


THE  METAL  WORKER’S  HANDY-BOOK. 


other,  and  for  this  reason  the  effect  must  be  constantly  controlled 
by  frequently  taking  the  objects  from  the  bath.  The  colors  succes¬ 
sively  formed  are  as  follows: 


Upon  copper. 

Orange, 
Terra-cotta, 
Red  (pale), 
Blood  red, 
Iridescent. 


Upon  brass. 

Golden-yellow, 

Lemon-color, 

Orange, 

Terra-cotta, 

Olive-green. 


Upon  nickel. 

Yellow, 

Blue, 

Iridescent. 


Some  of  these  colors  being  not  very  durable  have  to  be  pro¬ 
tected  by  a  coat  of  lacquer  or  paraffine.  It  is  further  necessary  to 
diligently  move  the  articles  so  that  all  portions  acquire  the  same 
color.  The  bath  decomposes  rapidly,  and  hence  only  sufficient  for 
2  or  3  hours’  use  should  be  mixed  at  one  time. 

Black  upon  Copper  is  produced  by  a  heated  pickle  consisting  of 
2  parts  of  arsenic  acid,  4  of  concentrated  hydrochloric  acid,  1  of 
sulphuric  acid  of  66°  Be.  and  24  of  water. 

Dead-black  on  Copper. — Brush  the  object  over  with  a  solution  of 
1  part  of  platinum  chloride  in  5  of  water,  or  dip  it  into  the  solu¬ 
tion.  When  dry  rub  it  with  a  flannel  rag  moistened  with  a  drop 
of  oil.  A  similar  result  is  obtained  by  dipping  the  copper  object 
in  a  solution  of  nitrate  of  copper  or  of  manganese  and  drying  over 
a  coal  fire.  The  manipulations  are  to  be  repeated  until  the  forma¬ 
tion  of  a  uniform  dead-black. 

To  Brown  Copper. — The  copper  to  be  browned  is  scoured  bright 
with  glass-paper,  strongly  heated  over  a  coal  fire,  and  brushed  over 
with  the  following  solution  :  Crystallized  acetate  of  copper,  5 
parts;  sal-ammoniac,  7;  dilute  acetic  acid,  3;  distilled  water,  85. 
Finally,  rub  the  article  with  a  solution  of  1  part  of  wax  in  4  parts 
of  oil  of  turpentine. 

Brow tiing  Liquid  for  Copper.— Add  acetic  acid  to  11  drachms  of 
spirit  of  sal-ammoniac  until  blue  litmus  paper  dipped  into  the 
liquid  turns  red.  Then  add  5^  drachms  of  sal-ammoniac  and 
sufficient  water  to  make  2.11  pints.  With  the  fluid  thus  obtained 
repeatedly  moisten  the  copper  surfaces,  rubbing  after  each  applica¬ 
tion  until  the  desired  brown  tint  is  obtained. 


BRONZING  AND  COLORING. 


171 


Imitation  of  Genuine  Patina. — Articles  of  copper  and  bronze 
exposed  for  a  long  time  to  the  action  of  the  air  acquire  a  beautiful 
brown  or  green  color,  which  considerably  contributes  to  their 
handsome  appearance.  This  color  is  known  as  Aerugo  nobilis 
(noble  rust),  or  patina. 

Though  there  are  many  agents  by  means  of  which  a  layer  of 
patina  can  be  produced  upon  the  bronze,  the  coating  thus  obtained 
cannot  compare  as  regards  beauty  and  durability  with  the  genuine 
patina. 

In  order  to  obtain  a  coating  similar  to  genuine  patina,  it  is  recom¬ 
mended  to  pursue  as  nearly  as  possible  the  same  course  by  which 
the  latter  is  naturally  formed.  By  the  action  of  rain,  which  always 
contains  salts,  though  in  very  minute  quantity,  in  solution,  the 
copper  is  attacked  and  basic  salts  of  copper  are  formed  upon  the 
surface,  which  are  in  the  course  of  time  converted  by  the  action  of 
the  carbonic  acid  of  the  air  into  basic  copper  carbonate.  The 
latter  has  a  beautiful  green  color,  and  is  found  in  nature  as  mala¬ 
chite.  But  besides  this  process  others  also  take  place  upon  the 
surface  of  the  article,  especially  upon  that  of  monuments  erected  in 
large  cities.  The  air  of  the  latter  is  constantly  charged  with  cer¬ 
tain  quantities  of  sulphur  combinations,  originating  partially  from 
the  putrefaction  of  excrements,  etc.,  in  the  sewers,  and  partially 
from  the  combustion  of  coal  containing  sulphur.  Now,  copper 
being  very  sensitive  to  the  action  of  sulphuretted  hydrogen,  a  coat¬ 
ing  of  black  cupric  sulphide  is  consequently  formed  upon  the  sur¬ 
face  of  the  object,  which  explains  why  bronze  statues  erected  in 
large  cities  frequently  turn  black.  Dust  and  fine  particles  of  soot, 
which  deposit  themselves  especially  in  the  depressions  of  the  object, 
further  contribute  to  their  becoming  black.  Cupric  sulphate  has, 
however,  the  property  of  becoming  rapidly  converted  in  the  air  into 
copper  sulphate,  from  which  is  again  formed  copper  carbonate,  or, 
so  to  say,  a  coating  of  malachite.  Genuine  patina,  especially  that 
observed  on  very  antique  statues,  consists,  therefore,  of  a  very  firmly 
adhering  coating  of  malachite. 

To  produce  upon  a  statue  a  patina-like  deposit,  brush  it  over  with 
a  very  dilute  solution  of  cupric  nitrate,  to  which  a  small  quantity 


172 


THE  METAL  WORKER’S  n ANDY- BOOK. 


of  common  salt  solution  may  be  added.  When  entirely  dry,  brush 
the  statue  with  a  fluid  consisting  of  ioo  parts  of  weak  vinegar,  5  of 
sal-ammoniac,  and  1  of  oxalic  acid,  and  repeat  the  application 
after  drying.  In  the  course  of  about  one  week  the  statue  will 
have  acquired  a  green-brown  color,  resembling  that  of  genuine 
patina. 

A  finer  coating,  which  more  closely  resembles  genuine  patina,  is, 
however,  obtained  by  dipping  the  article  into  the  solution  of  cupric 
nitrate,  and  placing  it  in  a  room  where  a  large  quantity  of  carbonic 
acid  is  developed,  the  fermenting-room  of  a  distillery  being  espe¬ 
cially  adapted  for  this  purpose,  since  the  high  temperature  prevail¬ 
ing  therein  promotes  the  formation  of  the  green  coating.  The 
progress  can  in  this  case  be  watched  from  day  to  day,  and  if  in 
about  a  week  the  statue  has  not  acquired  the  desired  coloration,  the 
application  of  the  above-mentioned  solution  is  repeated,  this  being 
continued  until  the  desired  tint  is  obtained.  The  formation  of  the 
patina  under  these  conditions  taking  place  in  a  similar  manner  as 
in  the  open  air,  a  very  beautiful  and  durable  coating  is  obtained. 

For  coating  articles  of  brass  with  a  green  patina ,  apply  a  solution 
prepared  by  dissolving  10  parts  of  copper  in  20  of  nitric  acid, 
diluting  the  solution  with  150  parts  of  vinegar,  and  adding  5  parts 
of  sal-ammoniac.  Allow  the  articles  to  stand  a  few  days  in  the  air, 
and  when  a  green  coloration  has  made  its  appearance,  brush  them 
with  old  linseed  oil,  and  after  a  few  days  rub  them  with  a  soft 
woollen  rag.  If  after  the  application  of  the  linseed  oil  the  article 
readily  bronzes,  a  very  beautiful  patina  will  soon  appear. 

There  are  several  methods  of  giving  an  agreeable  brown  patina 
to  medals.  It  is,  however,  most  readily  accomplished  by  heating 
the  medal  in  a  spirit-flame,  and  then  brushing  with  graphite.  To 
color  a  number  of  medals  at  the  same  time,  dissolve  30  parts  of 
verdigris  and  30  of  sal-ammoniac  in  100  of  water,  and  add  water 
to  the  solution  until  a  precipitate  is  no  longer  formed.  Place  the 
medals  without  touching  each  other  upon  the  bottom  ©f  a  shallow 
dish,  pour  the  boiling  hot  solution  over  them,  and  allow  them  to 
remain  until  they  have  acquired  the  desired  tint,  which  should  be 
a  fine  brown. 


BRONZING  AND  COLORING. 


173 


Another  Method  of  Imitating  Genuine  Patina  is  as  follows  :  Pre¬ 
pare  a  paint  by  triturating  copper  carbonate  with  a  pale  spirit  var¬ 
nish  (sandarac  varnish,  white  shellac  varnish),  and  apply  it  to  the 
article  with  a  brush.  The  greenish  paint  remains  in  the  depres¬ 
sions,  and  presents  a  patina-like  appearance.  Ordinary  verdigris 
gives  a  bluish  color,  and  crystallized  verdigris  a  pale-green  color. 
Various  intermediate  shades  may  be  obtained  by  mixing  these  two 
copper  combinations. 

Coloring  of  Brass  and  Bronzes. — Most  of  the  directions  given  for 
coloring  copper  are  also  available  for  brass  and  bronzes.  Many 
colorations  on  brass  are  effected,  however,  only  with  difficulty,  and 
are  not  entirely  successful,  as,  for  instance,  coloring  black  with 
liver  of  sulphur.  As  a  pickle  for  the  production  of  a 

Lustrous  Black  on  Brass  The  following  solution  serves  :  Dissolve 
freshly  precipitated  carbonate  of  copper  while  still  moist  in  strong 
liquid  ammonia,  using  sufficient  of  the  copper  salt  that  a  small 
excess  remains  undissolved,  or  in  other  words,  that  the  ammonia 
is  saturated  with  copper.  The  carbonate  of  copper  is  prepared  by 
mixing  the  hot  solutions  of  equal  parts  of  cupric  sulphate  (blue 
vitriol)  and  of  soda,  and  filtering  off  and  washing  the  precipitate. 

Dilute  the  solution  of  the  copper  salt  in  ammonia  with  one- 
fourth  its  volume  of  water,  add  31  to  46  grains  of  graphite,  and 
heat  to  950  or  104°  F.  Place  the  clean  and  pickled  objects  in  this 
pickle  for  a  few  minutes,  until  they  show  a  full  black  shade,  then 
rinse  in  water,  dip  in  hot  water,  and  dry  in  sawdust.  The  solution 
soon  spoils,  and  hence  no  more  than  required  for  immediate  use 
should  be  prepared. 

Steel-gray  on  Brass  is  obtained  by  the  use  of  a  mixture  of  1  lb. 
of  strong  hydrochloric  acid  with  x  pint  of  water,  to  which  is  added 
5)^  ozs.  of  iron-filings  and  a  like  quantity  of  pulverized  antimonic 
sulphide. 

Hydrochloric  acid  compounded  with  arsenious  acid  is  also  recom¬ 
mended  for  this  purpose.  The  mixture  is  brought  into  a  lead 
vessel,  and  the  objects  dipped  into  it  should  come  in  contact 
with  the  lead  of  the  vessel,  or  be  wrapped  around  with  a  strip  of 
lead. 


174 


THE  METAL  WORKER’S  HANDY-BOOK. 


Gray  color  with  a  bluish  tint  tipon  brass  is  produced  with  solu¬ 
tion  of  antimonious  chloride  (butter  of  antimony),  while  a  pure 
steel-gray  color  is  obtained  with  a  hot  solution  of  arsenious  chloride 
with  a  little  water. 

Straw-color  to  Brown  through  Golden  Yellow  and  Tombac  Color 
on  Brass  may  be  obtained  with  a  solution  of  carbonate  of  copper 
in  caustic  soda  lye.  Dissolve  5.29  ozs.  of  caustic  soda  in  1  quart 
of  water  and  add  1^  ozs.  of  carbonate  of  copper.  By  using  the 
solution  cold  a  dark  golden-yellow  is  first  formed,  which  finally 
passes  through  pale  brown  into  dark  brown  with  a  green  lustre  ; 
with  the  hot  solution  the  coloration  is  more  rapidly  effected. 

Color  Resembling  Gold  on  Brass. — According  to  Dr.  Kayser  a 
color  resembling  gold  is  obtained  as  follows :  Dissolve  8*4 
drachms  of  sodium  hyposulphite  in  17  drachms  of  water  and  add 
5.64  drachms  of  solution  of  antimonious  chloride  ( liquor  stibii 
chlorati).  Heat  the  mixture  to  boiling  for  some  time,  then  filter 
off  the  red  precipitate  formed,  and  after  washing  it  several  times 
upon  the  filter  with  vinegar,  suspend  it  in  2  or  3  quarts  of  hot 
water;  then  heat  and  add  concentrated  soda  lye  until  solution  is 
complete.  In  this  hot  solution  dip  the  clean  and  pickled  brass 
objects,  removing  them  frequently  to  see  whether  they  have  acquired 
the  desired  coloration.  The  articles  become  gray  by  allowing 
them  to  remain  too  long  in  the  bath. 

Brown  Color,  called  Bronze  Barbedienne,  on  Brass. — This  beauti¬ 
ful  color  may  be  produced  as  follows :  Dissolve  by  vigorous  shak¬ 
ing  in  a  bottle  freshly  precipitated  arsenious  sulphide  in  spirit  of 
sal-ammoniac,  and  compound  the  solution  with  antimonious  sul¬ 
phide  until  a  slight  permanent  turbidity  shows  itself  and  the  fluid 
has  acquired  a  deep  yellow  color.  Heat  the  solution  to  950  F.  and 
suspend  the  brass  objects  in  it.  They  become  at  first  golden-yellow 
and  then  brown,  but  as  they  come  from  the  bath  with  a  dark,  dirty 
shade  they  must  be  several  times  scratch-brushed  to  bring  out  the 
color.  If  after  using  it  several  times  the  solution  does  not  work 
satisfactorily  add  some  antimonious  sulphide.  The  solution  decom¬ 
poses  rapidly  and  should  be  prepared  fresh  every  time  it  is  to  be 
used. 


BRONZING  AND  COLORING. 


175 


Bronze  Barbedienne  on  Massive  Brass  or  brassed  articles  of  zinc 
or  iron  may  be  produced  as  follows  :  Mix  3  parts  of  pentasulphide 
of  cntimony  with  1  part  of  finely  pulverized  blood-stone,  and 
triturate  the  mixture  with  ammonium  sulphide  to  a  not  too  thickly- 
fluid  pigment.  Apply  this  pigment  to  the  objects  with  a  brush, 
and,  after  allowing  it  to  dry  in  a  drying  chamber,  remove  the 
powder  by  brushing  with  a  soft  brush. 

To  Color  Brass  Violet  and  Corn-flower  Blue. — Dissolve  in  1 
quart  of  water  4^  ozs.  of  sodium  hyposulphite,  and  in  another 
quart  of  water  1  oz.  3^  drachms  of  crystallized  sugar  of  lead,  and 
mix  the  solutions.  Heat  the  mixture  to  176°  F.  and  then  immerse 
the  articles,  moving  them  constantly.  First  a  gold-yellow  color¬ 
ation  appears  which,  however,  soon  passes  into  violet  and  blue, 
and,  if  the  bath  be  allowed  to  act  further,  into  green.  The  action 
is  based  upon  the  fact  that  in  an  excess  of  sodium  hyposulphite  a 
solution  of  hyposulphite  of  lead  is  formed  which  decomposes  slowly 
and  separates  sulphide  of  lead,  which  precipitates  upon  the  brass 
objects  and  produces  the  various  lustrous  colors. 

Similar  lustrous  colors  are  obtained  by  dissolving  2.11  ozs.  of 
pulverized  tartar  in  1  quart  of  water  and  1  oz.  of  chloride  of  tin  in 
y2  pint  of  water,  mixing  the  solutions,  heating  and  pouring  the 
clear  mixture  into  a  solution  of  6.34  ozs.  of  sodium  hyposulphite 
in  1  pint  of  water.  Heat  this  mixture  to  176°  F.  and  immerse  the 
pickled  brass  objects. 

Ebermayer' s  Method  of  Coloring  Brass. — In  testing  Ebermayer’s 
directions  Dr.  George  Langbein  did  not  always  obtain  the  same 
results  as  those  claimed  by  Ebermayer,  and  his  observations  are 
added  in  parenthesis  to  every  direction. 

1.  Sulphate  of  copper  (green  vitriol),  8  parts  by  weight ;  crystal¬ 
lized  sal-ammoniac,  2  ;  water,  100,  give  by  boiling  a  greenish  color. 
(The  color  is  olive-green,  and  useful  for  many  purposes.  The 
coloration  succeeds,  however,  only  upon  massive  brass,  but  not 
upon  brassed  zinc.) 

2.  Potassium  chlorate,  xo  parts  by  weight;  sulphate  of  copper, 
10  ;  water,  1000,  give  by  boiling  a  brown-orange  to  cinnamon-brown 
color.  (Only  a  yellow-orange  color  could  be  obtained.) 


176 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


3.  By  dissolving  8  parts  by  weight  of  sulphate  of  copper  in  1000 
of  water,  and  adding  100  of  caustic  soda  until  a  precipitate  is 
formed,  and  boiling  the  articles  in  the  solution,  a  gray-brown  color 
is  obtained,  which  can  be  made  darker  by  the  addition  of  col- 
cothar.  (Stains  are  readily  formed  ;  upon  brassed  zinc  a  pleasant 
pale  brown  is  formed.) 

4.  With  50  parts  by  weight  of  caustic  soda,  50  of  sulphide  of 
antimony,  and  500  of  water  a  pale  fig-brown  color  is  produced. 
(Fig-brown  could  not  be  obtained,  the  shade  being  rather  dark 

olive-green.') 

5.  By  boiling  400  parts  by  weight  of  water,  25  of  sulphide  of 
antimony,  and  60  of  calcined  soda,  and  filtering  the  hot  solution, 
mineral  kermes  is  precipitated.  By  taking  of  this  5  parts  by  weight 
and  heating  with  5  of  tartar,  400  of  water,  and  10  of  sodium  hypo¬ 
sulphite,  a  beautiful  steel-gray  is  obtained.  (The  result  is  tolerably 
sure  and  good.) 

6.  Water,  400  parts  by  weight ;  potassium  chlorate,  20  ;  nickel 
sulphide,  10,  give,  after  boiling  for  some  time,  a  brown  color,  which 
is,  however,  not  formed  if  the  sheet  has  been  pickled.  (The  brown 
color  obtained  is  not  very  pronounced.) 

7.  Water,  250  parts  by  weight ;  potassium  chlorate,  5  ;  carbonate 
of  nickel,  2  ;  and  nickel  salt,  5,  give,  after  boiling  for  some  time, 
a  brown-yellow  color  playing  into  a  magnificent  red.  (The  results 
obtained  were  only  indifferent.) 

8.  Water,  250  parts  by  weight ;  potassium  chlorate,  5  ;  nickel 
salt,  10,  give  a  beautiful  dark  brown.  (Upon  massive  brass  a  good 
dark  brown  was  obtained.  The  formula  is,  however,  not  available 
for  brassed  zinc.) 

To  Brighten  and  Color  Brass. — The  work  to  be  brightened  and 
colored  is  first  annealed  in  a  red-hot  muffle,  or  over  an  open  fire, 
allowing  the  cooling  to  extend  over  one  hour.  The  object  of  the 
heating  is  to  remove  the  grease  or  dirt  that  may  have  accumulated 
during  the  process  of  fitting.  Soft-soldered  work,  however,  must  be 
annealed  before  being  fitted  together,  and  afterwards  boiled  in  potash 
lye  ;  this  is  also  done  with  work  having  ornamental  surfaces.  Next, 
it  is  immersed  in  a  bath  of  dilute  nitric  acid,  which  may  be  made 


BRONZING  AND  COLORING. 


177 


with  2  or  3  parts  of  water  and  i  of  acid ;  but  the  old  acid  that 
contains  a  small  quantity  of  copper  in  solution  is  frequently  pre¬ 
ferred.  The  work  is  allowed  to  remain  in  this  liquid  for  i  or  2 
hours,  according  to  the  strength  of  the  acid ;  it  is  then  well  rinsed 
in  water,  and  scoured  with  sand  applied  with  an  ordinary  scrubbing- 
brush,  and  washed.  The  pickling  bath  is  made  by  dissolving  i 
part  of  zinc  in  3  of  nitric  acid  of  36°  Be.,  in  a  porcelain  vessel,  and 
adding  a  mixture  of  8  parts  of  nitric  acid  and  8  of  sulphuric  acid. 
Heat  is  then  applied,  and  when  the  liquid  is  boiling  the  work  is 
plunged  into  it  for  half  a  minute,  or  until  the  violent  development 
of  nitrous  vapor  ceases,  and  the  surface  is  becoming  uniform.  Then 
it  is  plunged  into  clean  water,  and  well  rinsed  to  remove  the  acid. 
The  ordinary  dark  grayish-yellow  tint,  which  is  thus  very  often 
produced,  is  removed  on  immersing  the  work  again  in  nitric  acid 
for  a  very  short  time.  Then  it  is  plunged  into  clean  or  slightly 
alkaline  water,  well  rinsed  to  remove  the  acid,  and  plunged  into 
warm,  dry  beech  or  boxwood  sawdust,  and  rubbed  until  quite  dry. 
To  prevent  the  action  of  the  atmosphere,  it  is  lacquered  ;  if  a  green 
tint  is  to  be  produced,  the  lacquer  is  colored  with  turmeric.  A 
dark  grayish,  but  agreeable  tint,  is  obtained  by  previously  immersing 
the  work  in  a  solution  of  white  arsenic  in  hydrochloric  acid,  or  in 
a  solution  of  bichloride  of  platinum,  with  the  addition  of  some 
vinegar,  or  rubbing  with  plumbago. 

Antimo7iy  Colors  on  Brass. — Dissolve  *4  oz.  of  cream  of  tartar  in 
1  lb.  of  hot  water,  and  add  1  y2  or  2  ozs.  of  hydrochloric  acid  and  a 
like  quantity  of  pulverized  metallic  antimony.  By  heating  the 
fluid  to  boiling  and  immersing  the  brass  objects,  the  latter  acquire 
a  beautiful  lustrous  color,  a  gold-yellow  tint  appearing  first,  which 
is  succeeded  by  a  beautiful  copper-red.  By  allowing  the  articles 
to  remain  longer  in  the  fluid,  the  copper-red  passes  into  a  beautiful 
blue-violet,  which  is  finally  succeeded  by  a  blue-gray.  The  colors 
are  constant,  and  do  not  change  by  exposure  to  the  air. 

Dead-black  on  Brass  Instruments. — Place  about  a  thimbleful  of 
lampblack  on  a  smooth  surface  of  glass  or  porcelain,  drop  4  or  5 
drops  of  gold  size  on  it,  and  thoroughly  incorporate  the  same  with 
a  spatula.  It  should  form  a  stiff  paste.  Use  as  little  of  the  size  as 
12 


178 


THE  METAL  WORKER'S  HANDY-BOOK. 


possible,  as  an  excess  will  give  the  coating  a  glossy,  instead  of  the 
desired  dead  finish.  Add  about  double  the  volume  of  turpentine; 
mix  with  a  camel’s-hair  brush,  and  apply  to  the  surface  to  be 
coated. 

Deep  Black-blue  Stain  on  Brass. — A  stain  which  produces  a  deep 
black-blue  layer  on  brass,  and  does  not  require  coating  with 
lacquer,  is  prepared  as  follows :  Dissolve  by  shaking  in  a  tightly 
closed  vessel  about  ozs.  of  copper  carbonate  in  1  y2  pint  of 
strong  spirits  of  sal-ammoniac.  The  quantity  of  copper  carbonate 
used  must  be  sufficiently  large  that  a  precipitate  (hydrated  oxide 
of  copper)  is  formed.  The  solution  thus  obtained  is  diluted  with 
about  y2  pint  of  water,  and  is  immediately  ready  for  use,  but  as  a 
rifle  produces,  after  a  few  days,  a  darker  and  finer  color  than  at  the 
start.  The  articles  cleaned  by  filing  or  turning  remain  in  the  fluid 
until  they  show  the  desired  color. 

Lustrous  Gold  or  Green  on  Brass. — French  articles  of  cast  or 
sheet  brass  are  made  of  a  cheap,  pale-colored  quality  of  brass,  but 
they  have  a  beautiful  gold  color  which  gives  them  a  fine  appearance 
and  makes  them  more  salable.  To  produce  this  color  the  follow¬ 
ing  process  is  used  :  Dissolve  4  parts  each  of  caustic  soda  and  milk 
sugar  in  100  parts  of  water.  Heat  the  solution  to  boiling  for  a 
quarter  of  an  hour ;  remove  the  vessel  containing  the  dark  yellow 
solution  from  the  fire  and  add,  with  stirring,  4  parts  of  a  cold  sat¬ 
urated  solution  of  sulphate  of  copper.  When  the  fluid  has  cooled 
off  to  about  165°  F. ,  and  after  the  separated  suboxide  of  copper 
has  settled,  the  clean  polished  articles  of  brass  are  introduced  into 
it  in  a  vessel  of  wood  with  perforated  bottom.  In  about  2  minutes 
the  golden  coloration  will  probably  be  dark  enough,  and  the  ar¬ 
ticles  are  removed,  washed  and  dried  in  saw  dust.  If  the  articles 
are  permitted  to  remain  for  a  longer  time  in  the  liquid  the  yellow¬ 
ish  color  at  first  developed  will  change  to  a  lustrous  bluish-green 
and  finally  to  iridescent  colors.  In  order  to  obtain  uniform  colora¬ 
tions  the  temperature  must  be  maintained  between  140°  and 
165°  F. 

The  copper  bath  may  be  used  repeatedly,  and  for  this  purpose 
should  be  kept  in  a  well-stoppered  flask.  When  it  has  become 


BRONZING  AND  COLORING. 


179 


spent  it  may  be  revivified  by  the  addition  of  i  part  of  caustic  soda, 
sufficient  water  to  replace  that  lost  by  evaporation,  heating  to  boil¬ 
ing  and  the  addition  of  2^  parts  of  sulphate  of  copper.  If,  in¬ 
stead  of  milk-sugar,  glycerine  or  a  bitartrate  is  used,  the  colors 
obtained  are  not  so  uniform. 

Gold  and  Orange  Stains  for  Brass. — Dip  the  articles  in  a  mix¬ 
ture  of  3  drachms  of  caustic  soda,  2  ozs.  of  water  and  5 ]/2  drachms 
of  moist  carbonate  of  copper.  The  shades  of  color  appear  in  a 
few  minutes,  and  the  progress  can  be  readily  judged  and  observed. 
After  obtaining  the  desired  shade  of  color  rinse  the  articles  in 
water  and  dry  in  fine  saw-dust. 

Beautiful  Silver  Color  on  Brass. — Dissolve  in  a  well-glazed  ves¬ 
sel  Of,  ozs.  of  pulverized  cream  of  tartar  and  drachms  of  tar¬ 
tar  emetic  in  1  quart  of  hot  water,  and  add  to  the  solution  1^  ozs. 
of  hydrochloric  acid,  4^  ozs.  of  granulated  or,  still  better,  pul¬ 
verized  tin  and  1  oz.  of  pulverized  antimony.  Dip  the  articles  to 
be  coated  in  the  solution  heated  to  the  boiling  point.  After  boil¬ 
ing  one-quarter  to  one-half  hour  they  will  be  provided  with  a 
beautiful  lustrous  coating,  which  is  hard  and  durable. 

New  Bronze-color  upon  Brass  and  Copper. — A  fluid  for  the  pro¬ 
duction  of  a  brown  bronze-color  upon  brass  and  copper  consists  of 
acetate  of  copper,  5^  parts;  sal-ammoniac,  7  ;  acetic  acid,  1  ;  and 
water,  100.  The  articles  to  which  this  fluid  is  to  be  applied  must 
before  each  application  be  vigorously  heated  over  a  coal  fire,  the 
beautiful  brown  color  frequently  appearing  only  after  thus  treating 
the  article  20  or  25  times.  With  skilful  manipulation  the  fluid 
gives  very  good  results.  For  coating  cast-bronze  wares  a  so-called 
Paris  bronze  lacquer  is  sold,  which  consists  simply  of  a  solution  of 
shellac  in  alcohol  with  the  addition  of  camphor.  A  solution  of  1 
part  of  shellac  in  8  or  xo  of  alcohol  and  adding  part  of  cam¬ 
phor  rubbed  up  with  a  few  drops  of  oil  of  lavender  gives  a  lacquer 
equal  to  the  commercial  article. 

To  Color  Copper  and  Brass. — By  dipping  a  piece  of  sheet  brass, 
brightly  polished  and  perfectly  clean,  in  a  dilute  solution  of  neu¬ 
tral  acetate  of  copper,  which  should  contain  not  a  trace  of  acid,  at 
a  medium  temperature  for  a  few  moments  it  acquires  an  extraor- 


180 


THE  METAL  WORKER’S  HANDY-BOOK. 


dinarily  beautiful  golden-yellow  color.  By  coating  brightly-pol¬ 
ished  sheet  brass  a  few  times  with  a  very  dilute  solution  of  chloride 
of  copper  it  appears  deadened  and  greenish-gray  bronzed.  By 
uniformly  heating  brightly-polished  brass  so  that  it  can  be  handled 
without  burning  the  hands  and  brushing  it  over  in  this  state  as 
rapidly  and  uniformly  as  possible  with  a  tuft  of  cotton  dipped  in  a 
solution  of  chloride  of  antimony  it  acquires  a  beautiful  violet  color. 

To  Whiten  Brass  and  Copper. — Small  articles  of  brass  and  cop¬ 
per  may  be  whitened  by  boiling  them  in  a  solution  of  ^  lb.  of 
cream  of  tartar,  2  quarts  of  water  and  1  lb.  of  grain  tin  or  any 
pure  tin  finely  divided.  The  tin  dissolves  in  the  cream  of  tartar 
and  is  again  precipitated  on  the  brass  or  copper. 

To  Blacken  Small  Iron  Articles  in  bulk. — A  deep  black  upon 
small  iron  articles  is  produced  by  heating  them  in  bulk  in  con¬ 
nection  with  oiled  saw-dust.  For  this  purpose  a  strong  sheet-iron 
drum  resembling  a  coffee-roaster  is  used.  It  consists  of  a  cylin¬ 
drical  body  provided  on  one  end  with  a  handle  for  turning,  and 
on  the  other  with  a  funnel  in  the  centre  of  which  is  the  aperture 
for  charging.  For  the  distribution  of  the  contents  strong  iron 
pins  are  rivetted  into  the  body  of  the  drum.  When  in  use  the  drum 
is  slowly  revolved  over  a  coal  or  gas  fire.  The  coloring  agent 
consists  of  an  intimate  mixture  of  10  parts  of  dry  saw-dust  and  1 
part  of  linseed  oil.  The  saw-dust  thus  oiled  is  shaken  in  the  drum 
together  with  the  articles  to  be  blackened  and  exposed  to  the  heat 
while  revolving  the  drum.  The  saw-dust  undergoing  combustion 
evolves  a  thick  smoke  which  cannot  immediately  escape  from  the 
drum,  it  passing  out  slowly  through  the  aperture  in  the  funnel. 
This  smoke  coats  the  articles  with  a  firmly  adhering  black  color. 
Care  must,  however,  be  had  not  to  expose  the  articles  too  long  to 
the  heat  as  otherwise  the  beautiful  black  is  replaced  by  a  gray  color. 
Hence  it  is  necessary  to  occasionally  examine  the  articles  as  to 
their  color.  When  they  show  the  proper  black  color  the  drum  is 
quickly  emptied  and  the  contents  are  spread  out  upon  sheet-iron 
to  cool. 

In  mixing  the  saw-dust  with  oil  care  must  be  had  not  to  exceed 
the  prescribed  proportions,  as  with  a  larger  quantity  of  oil  the 


BRONZING  AND  COLORING. 


181 


saw-dust  remains  adhering  to  the  articles  and  is  very  difficult  to 
remove. 

Lustrous  Black  on  Iron  is  obtained  by  the  application  of  a  solu¬ 
tion  of  sulphur  in  spirits  of  turpentine  prepared  by  boiling  upon 
the  water  bath.  After  the  evaporation  of  the  spirits  of  turpentine 
a  thin  layer  of  sulphur  remains  upon  the  iron,  which,  on  heating 
the  article,  intimately  combines  with  the  metal. 

By  another  method  the  cleansed  and  pickled  iron  articles  are 
coated  when  dry  with  linseed  oil  and  heated  to  a  dark  red.  If 
pickling  is  omitted  the  coating  with  linseed  oil  and  heating  have 
to  be  repeated  twice  or  three  times. 

According  to  Meriten  a  lustrous  black  on  iron  is  obtained  by 
placing  the  articles  as  anode  in  distilled  water  heated  to  158°  F.  and 
using  an  iron  plate  as  cathode.  A  layer  of  ferroso-ferric  oxide  is 
formed  which,  however,  can  only  be  obtained  in  a  firmly  adhering 
state  upon  wrought-iron.  The  lustre  appears  by  brushing  with  a 
soft  waxed  brush.  The  current  conducted  into  the  bath  must  only 
be  strong  enough  to  decompose  the  water  without  perceptible 
development  of  gas. 

Brown-black  Coating  with  Bronze  Lustre  on  Iron. — Heat  the 
bright  iron  objects  and  brush  them  over  with  a  concentrated  solu¬ 
tion  of  potassium  bichromate.  When  dry  heat  them  over  a  char¬ 
coal  fire  and  wash  until  the  water  running  off  shows  no  longer  a 
yellow  color.  Repeat  the  operations  twice  or  three  times.  A 
similar  coating  is  obtained  by  heating  the  iron  objects  with  a  solu¬ 
tion  of  10  parts  of  sulphate  of  iron  (green  vitriol)  and  1  part  of 
sal-ammoniac  in  wat&r. 

To  give  Iron  a  Silver-like  Appearance  with  High  Lustre. — Scour 
the  polished  and  pickled  iron  surfaces  with  a  solution  prepared  as 
follows  :  Heat  moderately  1  ozs.  of  chloride  of  antimony,  0.35  oz. 
of  pulverized  arsenious  acid  and  2.82  ozs.  of  elutriated  blood-stone 
with  1  quart  of  90  per  cent,  alcohol  upon  a  water  bath  for  half  an 
hour.  A  partial  solution  takes  place.  Dip  into  this  fluid  a  tuft  of 
cotton  and  go  over  the  iron  portions,  using  slight  pressure.  A  thin 
film  of  arsenic  and  antimony  is  thereby  precipitated,  which  is  the 


182 


TIIE  METAL  WORKER’S  IIANDY-BOOK. 


more  lustrous  the  more  carefully  the  iron  had  been  previously 
polished. 

To  Color  Iron  and  Steel  Blue. — Polish  and  cleanse  the  article 
thoroughly  with  lime  and  then  brush  it  over  with  the  following 
mixture  :  Butter  of  antimony,  8  parts  ;  fuming  nitric  acid,  8 ;  and 
hydrochloric  acid,  16.  Add  the  hydrochloric  acid  very  slowly 
and  drop  by  drop  to  avoid  heating.  Apply  the  mixture  to  the 
steel  with  a  rag  and  rub  with  green,  young  oak  wood  until  the 
desired  blue  color  is  produced. 

According  to  BSttger  a  durable  blue  on  iron  and  steel  may  be 
obtained  by  dipping  the  article  in  a  y2  per  cent,  solution  of  potas¬ 
sium  ferricyanide  (red  prussiate  of  potash)  mixed  with  an  equal 
volume  of  a  y2  per  cent,  solution  of  ferric  chloride. 

To  Color  Iron  and  Steel  Gray. — Polish  the  article,  and  coat  it 
with  a  mixture  of  butter  of  antimony,  8  parts,  and  sulphuric  acid, 
2  parts.  If  the  color  does  not  turn  out  handsome  enough  add  a 
few  drops  of  acetic  acid. 

Thieraulf  s  Process  for  Coloring  Wrought-iroa  and  Steel. — Thier- 
ault  has  invented  a  process  for  coloring  iron  and  steel  which  is  in¬ 
tended  at  the  same  time  to  protect  the  materials  from  rust  and  in¬ 
crease  the  beauty  of  their  appearance.  The  process  has  been  intro¬ 
duced  in  practice  and  has  proved  useful.  In  the  patent  specification 
the  following  mixtures  are  mentioned  as  suitable  for  the  execution  of 
the  process.  Fluid  No.  I  contains  chloride  of  mercury  and  sal-am¬ 
moniac;  No.  2  contains  chloride  of  iron,  sulphate  of  copper, 
nitric  acid,  alcohol  and  water;  No.  j,  ferrous  chloride  besides 
nitric  acid,  alcohol  and  water;  and  No.  4,  a  weak  solution  of 
potassium  sulphide.  The  articles  are  thoroughly  cleansed  from 
grease  by  immersion  in  boiling  potash  lye  and  rinsing  in  water, 
and  when  dry  are  twice  brushed  over  with  a  sponge  slightly  satu¬ 
rated  with  fluid  No.  1,  the  second  layer  being  applied  when  the 
crust  of  oxide  formed  upon  the  metal  is  entirely  dry  and  has  been 
rubbed  off  with  a  scratch-brush  and  iron  filings  and  dried  with 
linen.  The  remaining  operations  are  executed  in  the  same 
manner.  Several  layers  of  fluid  No.  2  are  next  applied  and  then 
fluid  No.  3,  the  sponge  being  thoroughly  soaked  with  the  latter, 


BRONZING  AND  COLORING. 


183 


After  drying  io  minutes  the  articles  are  thrown  into  a  bath  of  water 
at  1940  to  2120  F.,  in  which  they  remain  for  5  to  10  minutes 
according  to  their  bulk.  When  taken  out  and  dried,  a  few  more 
layers  of  fluid  No.  3  are  applied,  next  a  layer  of  fluid  No.  4,  and 
then  the  articles  are  again  immersed  in  hot  water.  When  taken 
from  the  bath  they  are  wiped  off  and  receive  several  more  layers  of 
fluid  No.  3  diluted  for  this  purpose  with  water.  They  are  then 
coated  with  a  thin  film  of  olive  oil,  washed  off,  immersed  in  water 
at  140°  F.  and,  when  taken  out,  rubbed  thoroughly  first  with  a 
woolen  rag  and  finally  with  a  little  olive  oil.  Articles  of  iron  and 
steel  thus  treated  have  a  beautiful  black,  lustrous  appearance, 
especially  when  polished. 

To  Blue  Small  Articles  of  Sheet-steel. — Dip  the  articles  in  a  fluid 
alloy  composed  of  lead,  25  parts;  and  tin,  1  part,  which  is  melted 
at  the  degree  of  heat  required  for  bluing.  The  immersion  may 
also  be  effected  in  a  sand  bath  heated  to  and  maintained  at  the 
required  temperature,  5720  F.  for  dark  blue,  478°  F.  for  pale  blue. 

To  Blue  Small  Articles  of  Iron  and  Steel  so  as  to  leave  Portions 
of  them  Bright.- — The  ground  and  finely  polished  work  is  blued, 
which  is  best  effected  over  a  thick  iron  plate  heated  red-hot.  In 
order  to  insure  uniformity  the  work  should  not  be  laid  directly 
upon  the  plate,  but  held  at  some  distance  over  it.  The  bluing 
being  effected,  which  will  be  the  finer  and  more  durable  the  better 
and  more  compact  the  material  used  in  the  work,  the  places  which 
are  to  remain  blue  are  covered  with  an  oil  paint  and  allowed  to 
dry  somewhat.  Heated  wine  vinegar  is  then  poured  over  the 
whole,  whereby  the  places  not  covered  by  the  oil  paint  immediately 
become  bright.  By  using  the  wine  vinegar  cold  it  must  act  about 
5  minutes,  and  the  surface  obtained  is  not  lustrous  but  a  dead 
white.  After  the  treatment  with  vinegar  the  work  is  dipped  into 
cold  water.  The  oil  paint  is  then  removed,  which  is  readily 
effected.  By  this  method  the  bright  places  retain  their  polish  and 
show  great  lustre. 

Coloring  of  Gold. — To  impart  to  articles  of  gold  alloys  a  color 
approaching  that  of  chemically  pure  gold  they  are  treated  with  a 
pickle  which  dissolves  the  copper  and  silver  on  the  surface  of  the 


184 


THE  METAL  WORKER’S  nANRY-BOOK. 


alloy  and  exposes  a  layer  of  pure  gold.  The  composition  of  this 
pickle  is  such  that  some  gold  is  also  dissolved,  but  it  precipitates 
at  once  upon  the  surface  of  the  object,  and  thus  effects  the  actual 
coloring.  The  composition  for  coloring  gold  articles  consists  of 
decrepitated  common  salt,  4^  ozs.  ;  saltpetre,  8. 1 1  ozs.  ;  and 
hydrochloric  acid,  6  ozs.  The  two  salts  are  finely  powdered  and 
intimately  mixed,  and  the  hydrochloric  acid  poured  over  them. 
The  mixture  is  boiled  until  chlorine  develops.  Suspend  the  gold 
articles  to  be  colored  to  a  glass-hook  or  platinum  wire  and  im¬ 
merse  them  in  the  boiling  mixture ;  take  them  out  after  3  to  5 
minutes  and  rinse  in  boiling  water.  If  the  desired  color  is  attained 
throw  the  objects  into  a  vessel  filled  with  water,  where  they  remain 
until  all  the  objects  are  colored.  Then  dip  them  successively  in 
boiling  water  and  dry  quickly.  If  the  proper  degree  of  coloration 
has  not  been  attained  repeat  the  immersion  in  the  bath.  By  the 
chlorine  developed  in  the  coloring  bath  chlorides  of  copper,  silver 
and  gold  are  formed.  The  latter  are,  however,  in  consequence 
of  the  content  of  copper  in  the  alloy,  decomposed  and  the  pure 
gold  is  precipitated  in  a  more  or  less  thick  layer.  As  in  coloring 
gold  it  is  absolutely  necessary  to  employ  a  fluid  which  develops 
chlorine  in  abundance,  dilute  aqua  regia  compounded  with  a  cor¬ 
responding  quantity  of  common  salt  may  be  directly  used  in  case 
the  alloy  contains  silver.  A  suitable  mixture  is  as  follows :  Con¬ 
centrated  hydrochloric  acid,  31  parts  by  weight;  concentrated 
nitric  acid,  10;  common  salt,  20;  and  water,  40.  In  this  bath 
the  articles  must  remain  only  a  very  short  time,  as  otherwise  the 
surface  becomes  dead  and  lustreless. 

Bronze-like  Patina  upon  Tin. — Brush  the  object  over  with  a 
solution  of  1^  ozs.  of  sulphate  of  copper  (blue  vitriol)  and  a  like 
quantity  of  ferrous  sulphate  (green  vitriol)  in  1  quart  of  water,  and 
moisten  the  dried  object  with  a  solution  of  3)^  ozs.  of  verdigris  in 
10^2  ozs.  of  vinegar.  When  dry,  polish  the  object  with  a  soft  brush 
rubbed  upon  wax  and  some  ferric  oxide.  The  coating  thus  obtained 
being  not  especially  durable  must  be  protected  by  a  coating  of 
lacquer. 

Sepia-brown  on  Tin  and  its  Alloys. — Brush  the  object  over  with  a 


BRONZING  AND  COLORING. 


185 


solution  of  i  part  of  platinum  chloride  in  io  of  water,  allow  the 
coating  to  dry,  then  rinse  in  water,  and,  after  again  allowing  to 
dry,  brush  with  a  soft  brush  until  the  desired  brown  lustre 
appears. 

A  dark  coloration  is  also  obtained  with  a  solution  of  ferric 
chloride. 

Coloring  Zinc. — The  results  obtained  by  coloring  zinc  directly 
according  to  existing  directions  cannot  be  relied  on,  and  it  is, 
therefore,  recommended  to  first  copper  the  zinc  and  then  color  the 
coppering.  Experiments  in  coloring  zinc  black  with  alcoholic 
solution  of  chloride  of  antimony  according  to  Dullos’s  process 
gave  no  useful  results.  Puscher’s  method  is  better ;  according  to  it 
the  articles  are  dipped  in  a  boiling  solution  of  5.64  ozs.  of  pure 
green  vitriol  and  3.17  ozs.  of  sal-ammoniac  in  2^  quarts  of  water. 
The  loose,  black  precipitate  deposited  upon  the  articles  is  removed 
by  brushing,  the  article  again  dipped  in  the  hot  solution  and  then 
held  over  a  coal-fire  until  the  ammonia  salt  evaporates.  By  repeat¬ 
ing  the  operation  three  or  four  times  a  firmly-adhering  black  coat¬ 
ing  is  formed.  To  color  zinc  black  with  nitrate  of  manganese,  as 
proposed  by  Neumanns,  is  a  tedious  operation,  it  requiring  to  be 
repeated  seven  or  eight  times.  It  is  done  by  dipping  the  article 
in  a  solution  of  nitrate  of  manganese  and  heating  over  a  coal-fire, 
the  manipulations  being  repeated  until  a  uniform  dead-black  is 
formed. 

By  suspending  zinc  in  a  nickel-bath  slightly  acidulated  with  sul¬ 
phuric  acid,  a  firmly  adhering  blue-black  coating  is  after  some  time 
formed  without  the  use  of  a  current.  This  coating  is  useful  for 
many  purposes.  A  similar  result  is  attained  by  immersing  the 
zinc  articles  in  a  solution  of  2.11  ozs.  of  the  double  sulphate  of 
nickel  and  ammonium  and  a  like  quantity  of  sal-ammoniac  in  x 
quart  of  water.  The  articles  become  first  dark  yellow,  then  suc¬ 
cessively,  brown,  purple-violet  and  indigo-blue ,  and  stand  slight 
scratch-brushing  and  polishing. 

Gray  Coating  on  Zinc  is  obtained  by  a  precipitation  of  arsenic 
in  a  heated  bath  of  2.82  ozs.  of  arsenious  acid,  8.46  drachms  of 
sodium  pyrophosphate  and  1^  drachms  of  98  per  cent,  potassium 


18C 


TPIE  METAL  WORKER’S  HANDY-BOOK. 


cyanide  to  i  quart  of  water.  A  strong  current  should  be  used  so 
that  a  vigorous  development  of  hydrogen  is  perceptible.  Platinum 
sheets  or  carbon  plates  are  used  as  anodes. 

Green  Coating  on  Zinc. — Zinc  articles  maybe  provided  with  a 
permanent  dark  or  light  green  coating  resembling  enamel  as  fol¬ 
lows:  Dissolve  50  parts  of  hyposulphite  of  sodium  in  500  of  boil¬ 
ing  water,  and  at  once  pour  the  solution  in  a  fine  stream  into  25 
parts  of  sulphuric  acid.  The  milk  of  sulphur  that  separates  will 
soon  ball  together  in  lumps  and  settle.  The  hot  liquid  containing 
sulphate  of  sodium  and  sulphurous  acid  is  decanted  and  the 
cleansed  zinc  placed  in  it.  In  a  short  time  it  will  acquire  a  very 
brilliant  light-green  coating,  which  only  needs  to  be  washed  and 
dried.  By  exposing  it  for  a  longer  time  to  this  hot  bath  the  coat¬ 
ing  grows  thicker  and  the  color  darker  and  more  brilliant.  To 
insure  a  fine,  brilliant  deposit  the  temperature  should  not  be  allowed 
to  fall  below  145°  F.  By  dipping  the  articles  thus  treated  in 
diluted  hydrochloric  acid  (1  acid  to  3  water)  sulphuretted  hydrogen 
is  evolved,  and  this  enamel-like  coating  loses  its  lustre  and  becomes 
lighter  in  color.  Aqueous  solutions  of  aniline  colors  have  little 
effect  upon  this  dull  surface,  and  none  whatever  on  the  brilliant 
coating. 

The  effect  of  marbling  may  be  obtained  by  moistening  the  gray 
zinc  and  applying  hydrochloric  acid  in  spots  with  a  sponge,  then 
rinsing  off  and,  while  still  wet,  flowing  over  it  an  acidified  solution 
of  sulphate  of  copper  which  produces  the  appearance  of  black 
marble.  As  this  has  a  dull  surface  it  should  be  varnished. 

By  adding  15  parts  of  chrome  alum  and  15  more  of  the  hyposul¬ 
phite  to  the  above  solution,  the  article  treated  will  take  on  a 
brownish  color. 

Bronze-color  on  Zinc. — A  sort  of  bronzing  on  zinc  is  obtained 
by  rubbing  it  with  a  paste  of  pipe-clay  to  which  has  been  added  a 
solution  of  1  part  by  weight  of  crystallized  verdigris,  1  of  tartar 
and  2  of  crystallized  soda. 

Copper-red  on  Zinc. — Immerse  the  article  in  a  bath  of  chloride 
of  copper  dissolved  in  spirits  of  sal-ammoniac.  If  the  color  is  to 
have  a  yellowish  tone  add  some  crystallized  verdigris. 


BRONZING  AND  COLORING. 


187 


Red-brownish  Color  on  Zinc. — Rub  with  a  solution  of  chloride 
of  copper  in  liquid  ammonia. 

Yellow-brown  Shades  on  Zinc. — Rub  with  a  solution  of  chloride 
of  copper  in  vinegar. 

To  Brown  Gun-barrels. — Mix  chloride  of  antimony  to  a  creamy 
consistency  with  olive  oil.  Apply  the  mixture  evenly  to  the  heated  4 
barrel,  allow  it  to  act  for  12  to  24  hours,  then  remove  the  excess 
with  a  woolen  rag  and  repeat  the  operation.  After  the  second  ap¬ 
plication  has  acted  for  12  to  24  hours,  the  iron  or  steel  is  covered 
with  a  bronze-like  layer  of  ferric  oxide  and  antimony,  which  resists 
the  action  of  the  air  and  may  be  made  lustrous  by  brushing  with  a 
waxed  brush.  The  sharpening  of  the  chloride  of  antimony  can  be 
effected  by  adding  a  little  nitric  acid  to  the  paste  of  olive  oil  and 
chloride  of  antimony  so  as  to  hasten  the  operation.  Another 
formula  is,  nitric  acid,  1.5  parts;  sweet  spirit  of  nitre,  1.5; 
rectified  alcohol,  3  ;  blue  vitriol,  6 ;  tincture  of  chloride  of  iron, 

3 ;  distilled  water,  100.  Dissolve  the  blue  vitriol  in  the  water, 
then  add  the  other  materials.  The  burnishing  and  marking  can  be 
effected  with  the  burnisher  and  scratch-brush.  The  polishing  is 
best  effected  by  rubbing  with  a  piece  of  smooth,  hard  wood,  called 
polishing  wood.  The  barrel  is  finely  varnished  with  shellac  var¬ 
nish  and  again  polished  with  the  hard-wood  polisher.  Some  prefer 
the  tone  of  brown  produced  by  blue  vitriol,  5  parts ;  sweet  spirit 
of  nitre,  5  ;  water,  100.  In  any  case  the  surface  of  the  iron  must 
be  well  cleansed  and  rendered  quite  bright;  it  is  then  freed  from 
grease  by  rubbing  with  whiting  and  water,  or  better,  with  powdered 
quick  lime  and  water.  The  browning  composition  is  then  put 
on  and  allowed  to  remain  24  hours.  It  is  then  rubbed  off  with  a 
stiff  brush.  If  not  sufficiently  browned  repeat  the  last  process  after 
browning.  Clean  the  surface  well  with  hot  water  containing  a 
little  soda  or  potash,  and,  lastly,  with  boiling  water,  and  dry  it. 
The  surface  can  be  burnished  and  polished.  Varnish  with  tin¬ 
smith’s  lacquer,  or  with  gum  shellac,  2  ozs.  ;  dragon’s  blood,  3 
drachms;  methylated  spirit  of  wine,  4  pints.  The  metal  should 
be  made  hot  before- applying  this  varnish,  and  it  will  present  an 
excellent  appearance.  If  the  varnish  is  not  required  to  color,  but 


188 


THE  METAL  WORKER’S  HANDY-BOOK. 


only  to  preserve  the  actual  tint  produced  on  the  metal  surface  by 
the  browning  fluid,  leave  out  the  dragon’s  blood. 

Another  Method  of  Browning  Gun-barrels  is  as  follows  :  Mix 
1 6  parts  of  sweet  spirit  of  nitre,  12  parts  of  a  solution  of  sulphate 
of  iron,  a  like  quantity  of  butter  of  antimony  and  16  parts  of  sul¬ 
phate  of  copper.  Let  the  mixture  stand  in  a  well-corked  bottle  in 
a  moderately  warm  place  for  24  hours,  then  add  500  parts  of  rain 
water  and  put  it  away  for  use. 

After  the  barrel  has  been  rubbed  with  emery  paper  and  polished, 
wash  it  with  fresh  lime  water,  dry  thoroughly,  and  then  coat  it  over 
uniformly  with  the  above  mixture  ;  it  is  best  to  use  a  tuft  of  cotton. 
Let  it  dry  for  24  hours  and  then  brush  it  with  a  scratch-brush.  Re¬ 
peat  the  coating  and  drying  twice,  but  in  rubbing  off  for  the  last 
time  use  leather  moistened  with  olive  oil  in  place  of  the  scratch¬ 
brush,  and  rub  until  a  beautiful  lustre  is  produced,  then  let  it  dry 
for  12  hours  and  repeat  the  polishing  with  sweet  oil. 

To  Blacken  Damasked  Gun-barrels. — The  finely  polished  barrel 
is  coated  by  means  of  a  woolen  rag  with  a  very  thin  layer  of  olive 
oil  and  then  dusted  over  with  hard-wood  ash.  It  is  next  blackened 
by  heating  over  glowing  coals,  and  after  removal  from  the  fire 
allowed  to  cool.  When  cool  it  is  brushed  over  with  water  con¬ 
taining  a  few  drops  of  hydrochloric  acid  to  the  pint  and  then 
quickly  washed  with  tow  or  coarse  linen  and  water.  Of  the  dam¬ 
ask  thus  treated  the  steel  portions  become  white,  while  the  iron 
portions  appear  black.  When  the  operation  is  finished  the  barrel 
is  carefully  dried  and  finally  rubbed  with  oil. 

To  Brown  Medals  and  Coins. — Boil  a  solution  of  2  parts  of 
verdigris  and  1  of  sal-ammoniac  in  vinegar,  and  after  removing  the 
scum,  dilute  with  water  until  it  shows  only  a  slight  metallic  taste 
and  no  more  white  precipitate  is  formed.  Pour  off  the  fluid  from 
the  precipitate,  bring  it  to  the  boiling  point  as  rapidly  as  possible, 
and  immediately  pour  it  over  the  polished  and  clean  medals,  which 
should  rest  with  the  edges  upon  a  wooden  or  copper  grate  on  the 
bottom  of  the  vessel  in  such  a  manner  that  only  two  points  of  the 
periphery  touch  the  bars  of  the  grate.  Examine  at  least  every  five 
minutes  whether  the  desired  color  has  been  obtained,  because  by 


CASTING  AND  FOUNDING. 


189 


remaining  too  long  in  the  fluid  the  coating  becomes  scaly  and  dead. 
When  the  medals  have  acquired  an  agreeable,  red-brown,  lustrous 
color  pour  off  the  solution  and  immediately  wash  carefully  and 
repeatedly  with  much  water.  The  solution  used,  which  has  become 
concentrated  by  boiling,  can  be  again  employed  by  diluting  with 
water  and  some  vinegar.  The  more  dilute  the  solution,  the  slower 
the  process  of  browning  takes  place;  the  success  of  the  operation 
is,  however,  also  more  certain.  A  too  strong  solution  gives  a  coat¬ 
ing  which  peels  off  on  rubbing. 


VII. 

CASTING  AND  FOUNDING. 

A  metal  to  be  suitable  for  casting  should  possess  the  following 
properties:  i.  It  must  be  fusible  without  great  difficulty.  2.  The 
casting  made  of  it  must  show  a  homogeneous  structure.  3.  It  must 
fill  out  the  mould  sharply  and  accurately. 

Gray  pig-iron  especially  excels  in  these  three  points,  its  ap¬ 
plicability  for  so  many  purposes  depending  on  these  properties; 
next  come  the  metallic  alloys,  brass,  bronze,  gun-metal,  type-metal 
and  the  various  mixtures  of  lead  and  tin.  It  will  be  readily  under¬ 
stood  that  a  thickly-fluid  metal  cannot  penetrate  into  the  fine 
depressions,  and  hence,  will  not  fill  the  mould  accurately,  this 
being  especially  noticeable  with  tin  by  itself.  On  the  other  hand  a 
mixture  of  tin,  lead  and  bismuth  is  very  thinly  liquid.  At  a  higher 
temperature  white  pig-iron  becomes  pasty,  and  consequently  is  not 
suitable  for  casting. 

Shrinking  of  Metals  in  Casting. — With  the  exception  of  cast-iron 
all  metals  in  congealing  have  the  property  of  contracting,  i.  e.,  of 
occupying  a  smaller  space;  a  further  contraction  takes  place  during 
the  cooling  of  the  congealed  metal.  The  volume  of  cast-iron  in¬ 
creases  at  the  moment  of  congelation,  and  consequently  the  sides 
of  the  mould,  if  yielding  as  in  ordinary  sand  moulds,  will  be  forced 


190 


THE  METAL  WORKER’S  HANDY-BOOK. 


apart.  After  congealing  the  ordinary  contraction  also  takes  place 
in  iron. 

Hence,  all  castings  when  completely  cooled  off  will  be  smaller 
than  the  pattern  or  the  mould.  This  contraction  of  the  metals  in 
casting  is  called  “shrinking.”  If,  therefore,  a  casting  is  to  fit 
other  pieces  already  finished  or  designed  of  determined  size  the 
pattern  must  be  made  larger,  in  proportion  to  the  shrinkage. 

The  pattern  is  the  model  of  which  the  casting  is  to  be  the  copy, 
but  an  intermediate  stage  is  necessary,  namely,  the  mould,  which 
represents  in  hollows  the  projections  which  must  appear  on  the 
finished  casting.  Each  of  these  articles,  namely,  the  pattern,  the 
mould  and  the  casting,  is  generally  made  in  different  materials, 
each  of  which  is  subject  to  certain  alterations  in  size  and  shape, 
dependent  upon  the  degree  of  heat  to  which  it  may  be  exposed,  or 
upon  changes  in  dryness  or  moisture.  Thus,  from  the  original 
design  or  drawing  a  pattern  is  made,  most  frequently  in  wood, 
which  is  then  transferred  to  the  mould ;  this  varies  in  materials 
according  to  the  nature  of  the  work  into  which  finally  the  molten 
metal  is  poured.  In  view  of  these  circumstances,  and  certain 
known  properties  of  materials  at  different  temperatures,  allowances 
have  to  be  made  for  shrinkage,  etc.  The  casting  itself  contracts 
in  cooling  to  an  extent  which  is  pretty  well,  but  by  no  means  ac¬ 
curately  ascertained,  and  for  which  a  regular  allowance  is  made. 
Thus,  in  large,  heavy  castings,  inch  is  added  to  every  foot  of 
length  in  the  pattern,  which  is  found  in  practice  sufficient  to  allow 
for  the  contraction  of  the  metal  on  cooling,  combined  as  it  is  with 
the  slight  increase  in  the  size  of  the  mould  over  the  pattern.  In 
small  castings  inch  to  the  foot,  or  about  i  per  cent.,  is  suf¬ 
ficient. 

The  following  table  gives  the  results  of  practical  observations  on 
the  shrinkage  of  metals  in  casting,  and  is  very  simple  in  applica¬ 
tion.  Thus,  a  cast-iron  girder  20  feet  long  must  have  a  pattern 
0.1246  X  20  =  2.492  inches  longer  than  itself,  but  a  pattern  20 
feet  long  would  give  a  casting  0.1236  X  20  =  2.472  inches  shorter 
than  itself. 


CASTING  AND  FOUNDING. 


191 


Contraction  of  Metals  in  Casting. 


Cast-iron  girder . 

tt  tt 

Gun-metal  bar . 

it  it 

((  tt 

it  tt 

tt  tt 

tt  tt 

ft  it 

((  tt 

««  << 

Copper  and  tin ;  copper, 
1.3;  tin,  ro. 

it  a  ti 

tt  it  it 

ft  ft  ft 

ft  ft  ft 

Yellow  brass  . 

Copper . : . . . . 

ft 


if 


ft 

Lead  (mould)... 
Zinc  cast  in  iron, 

if  ft 

tt  ft 


Length 

Contraction. 

of 

pattern. 

Total  in 
inches. 

Per  foot 
of 

pattern. 

Per  foot 
of 

casting. 

ft. 

21 

in. 

8X 

3-1 

0.1236 

0.1246 

16 

9 

2.05 

0.1225 

0.1236 

5 

4% 

1.0 

0.18568 

0.1886 

Maximum 

S 

7U 

0.936 

0.1653 

0.1676 

“ 

0.97 

0.1713 

0.1737 

6 

°x 

1.0 

0. 1616 

0.1684 

5 

6tV 

it 

0.92 

0.1671 

0.1695 

ft 

0.90 

0.1635 

0.1657 

it 

0.88 

0.1598 

0.1620 

it 

if 

0.84 

0.1526 

0.1545 

Minimum 

5 

ft  3 
°T5 

0.895 

0.1607 

0.1623 

0.1632 

0.1645 

Mean  of  8 

Maximum 

“ 

tt 

0.880 

0.1595 

0.1617 

it 

tt 

0.880 

0-1595 

0.1617 

it 

it 

0.855 

0.1550 

0.1570 

Minimum 

it 

a 

0.1591 

0.1612 

Mean  of  4 

2 

9'/s 

5 

0.1811 

0.1839 

7 

iof8 

i-54 

0.1948 

0.1980 

Minimum 

7 

5/s 

1.465 

0.1972 

0.2005 

it 

tt 

0.1972 

0.2005 

Maximum 

2 

O 

0.21 

0.1964 

0.1050 

0.1996 

0.1059 

Mean  of  4 

2 

A  3 
°T5 

0.455 

0.2257 

0.2301 

Minimum 

it 

it 

0.465 

0.2307 

0.2352 

Maximum 

it 

ft 

0.2282 

0.2326 

Mean  of  2 

For  practical  purposes  the  following  may  be  taken  as  sufficient 
approximations : 


In  locomotive  cylinders 

In  pipes  = 

Girders,  beams,  etc.  =  in  15  inches. 

Engine  beams,  connecting  rods  =  %  in  16  inches. 

In  large  cylinders,  say  70-inch  diameter, 

10  feet  stroke,  the  contraction  of  diameter  =  at  top. 

Ditto  =  y2  at  bottom. 

Ditto  in  length  =  y&  in  16  inches. 


192 


THE  METAL  WORKER’S  HANDY-BOOK. 


In  thin  brass 
In  thick  brass 
In  zinc 
In  lead 
In  copper 
In  bismuth 
Ill  tin 


=  yfa  in  9  inches. 

=  *4  in  io  inches. 
=  t5j  in  a  foot, 
from  '/%  to  in  a  foot. 
=  t3j  in  a  foot. 

=  in  a  foot, 
from  x*2  to  in  a  foot. 


Easy  Rule  to  Find  Approximate  Weight  of  Castings. — Thickness 
in  Yq  of  inches  X  width  in  of  inches  X  length  in  feet  =  lbs. 
weight  cast-iron;  for  lead  add  to  the  result  one-half;  for  brass 
add  one-seventh,  and  for  copper  one-fifth. 

Weight  of  Castings. — The  following  table  gives  the  weight  of  a 
pattern  weighing  i  lb.  when  cast  in  different  metals: 


A  pattern  weighing  1  lb. 

Will  w 

eigh  when  cast  in 

Cast-iron. 

Zinc. 

Copper. 

Yellow 

brass. 

Gun-metal 

Mahogany . 

8 

8 

IO 

9.8 

IO 

White  pine . 

14 

14-5 

18 

17-5 

17.8 

Yellow  pine . 

13 

12.6 

16 

15-5 

16 

Cedar . 

11. 5 

11  4 

14.5 

14 

14-5 

Maple . 

IO 

9.8 

12.5 

12 

12.4 

Moulding  Sand  for  Castings  of  Ingot-iron. — This  mass  serves  for 
the  manufacture  of  dense  and  smooth  castings  of  ingot-iron,  and 
consists  of  a  mixture  of  from  1464  to  1831  cubic  inches  of  sharply- 
burnt,  pulverized  and  entirely  pure  refractory  clay  with  61  cubic 
inches  of  sugar,  2  quarts  of  water  and  \  quart  of  paraffine  oil. 
Before  use  the  mixture  is  several  times  sifted  to  insure  a  uniform 
distribution  of  the  moisture ;  an  admixture  of  silicic  acid,  lime, 
magnesia  or  charcoal  must  be  carefully  avoided. 

To  Prevent  the  Baking  of  Moulding  Sand. — Moulding  sand  con¬ 
sists  chiefly  of  quartz  sand  and  clay,  the  latter  serving  as  a  cement 
for  the  former.  The  availability  of  the  sand  for  moulding  is 
dependent  on  its  fineness  and  the  proportion  of  the  above- 
mentioned  constituents.  The  content  of  clay,  on  the  one  hand, 


CASTING  AND  FOUNDING. 


193 


must  not  be  so  large  that  the  sand  becomes  hard  by  the  slight 
glowing  caused  by  contact  with  the  fluid  metal,  and,  on  the  other, 
must  be  sufficiently  large  to  impart  to  the  sand  the  required 
coherence  after  moistening  and  pressing  together.  The  baking  of 
moulding  sand  is  decreased  by  an  addition  of  soot  and  coal  powder, 
and  promoted  by  an  addition  of  beer  yeast,  beer,  molasses,  rye- 
flour,  etc.  A  content  of  lime  is  injurious  to  moulding  sand.  In 
many  places  available  moulding  sand  is  found  which  need  only  to 
be  comminuted  and  sifted  to  be  ready  for  use.  Where  such  natural 
moulding  sand  cannot  be  had,  it  may  be  prepared  by  mixing  93 
parts  of  pure  quartz  sand  with  7  parts  of  clay  free  from  lime. 
Moulding  sand  which  has  been  used  and  has  partially  lost  its 
cementing  power  can  be  restored  by  mixing  with  fresh  sand. 
Moulding  sand  should  not  be  stored  in  the  open  air,  since  the  finer 
particles  of  clay  are  washed  out  by  the  rain. 

Moulding  a?id  Moulds. — Almost  all  general  machine  moulding 
is  done  in  green  sand,  which  is  moulding  sand,  moistened  suf¬ 
ficiently  to  cause  it  to  adhere ;  and  work  in  which  particular  care 
is  to  be  taken  is  done  in  dry  sand.  This  is  sand  which  has  been 
dampened,  the  same  as  green  sand,  and  then  put  in  an  oven  and 
thoroughly  dried,  which  sets  the  mould  in  shape.  It  is  claimed 
that  by  thus  drying  the  sand  the  casting  will  be  saved  from  sand- 
holes.  Another  advantage  of  dry  sand  moulding  is  that  the  mould 
can  be  tipped  on  end  and  make  the  casting  endwise  to  insure 
soundness,  as  the  pressure  of  the  metal  from  above  causes  a  solid 
settlement  towards  the  bottom  of  the  casting.  Thus  it  is  claimed 
by  this  method  that  a  more  solid  and  sounder  casting  can  be  made 
than  by  the  use  of  green  sand,  in  which  the  casting  must  be  done 
flat,  as  the  sand  would  not  otherwise  adhere  and  the  mould  would 
be  spoiled.  The  first  step  in  moulding,  after  the  moulder  receives 
his  pattern  of  the  article  to  be  cast  from  the  pattern-maker,  is  the 
making  of  the  flask  or  box  in  which  moulding  sand  and  the  pattern 
are  to  be  placed.  This  flask  is  built  upon  the  idea  of  allowing 
room  for  the  pattern  and  moulding  sand.  The  flask  is  generally  a 
box  of  pine  wood  or  iron.  The  white  pine  flask  must  be  made 
strong  enough  to  stand  the  pressure  of  metal  and  the  weight  of 
13 


194 


THE  METAL  WORKER’S  HANDY-BOOK. 


sand  in  the  box.  The  pine  boards  are  put  together  with  dowel 
pins,  so  that  when  the  flask  is  taken  apart  it  can  be  easily  made  up 
again. 

Wooden  flasks  are  made  for  green  sand  moulding,  but  all  flasks 
made  for  dry  sand  moulding  are  made  of  iron,  because  these 
moulds  have  to  be  put  in  an  oven  and  kept  there  until  the  sand  is 
thoroughly  dry,  and  the  pine  boards  would  not  stand  the  heat.  In 
flasks  for  both  green  and  dry  sand  moulding  there  are  bars  sticking 
from  the  upper  and  side  interior  surface  of  the  flask  to  hold  the 
sand  in  place.  Some  of  these  bars  have  little  pieces  set  on  at  right 
angles  to  the  end,  or  little  hooks,  which  aid  in  holding  the  sand 
in  place  in  addition  to  the  adhesiveness  caused  by  the  dampening 
in  the  green  sand  and  afterwards  by  the  drying  or  baking  of  the 
dry  sand  mould.  These  bars  extend  from  the  interior  surface  of 
the  flask  to  within  a  few  inches  of  the  pattern,  and  without  them 
the  sand  would  probably  not  hold  its  form  after  the  pattern  is 
withdrawn.  The  flask  is  generally  made  of  three  or  more  pieces 
so  that  it  can  be  taken  apart  and  the  pattern  taken  out  after  the 
mould  is  formed.  The  flask  having  been  prepared,  a  certain 
quantity  of  the  wet  or  dampened  moulding  sand  is  taken  and 
rammed  down  hard  into  place,  and  then  the  pattern  is  put  in  and 
covered  up  with  damp  moulding  sand,  which  is  also  rammed  down 
firm.  After  the  pattern  is  covered  up  and  the  whole  interior  flask 
filled  up,  it  is  secured  and  the  whole  allowed  to  rest  a  while  until 
it  is  thoroughly  set  and  the  pattern  is  taken  out,  the  upper  part  of 
the  flask  and  mould  replaced,  and  the  mould  is  ready  for  the  metal. 
The  dry  sand  flask,  after  being  thoroughly  and  solidly  filled  with 
wet  sand,  is  carried  to  the  oven  and  baked  until  the  sand  is  thor¬ 
oughly  dry  and  set,  the  time  depending  on  the  size  of  the  flask  and 
the  amount  of  sand.  Then  it  is  removed,  the  pattern  taken  out, 
and  the  mould  is  ready  for  the  casting.  The  dry  sand  mould  being 
baked  holds  together  very  well,  as  may  be  easily  understood,  but 
it  appears  singular  that  the  green  sand  will  hold  together,  but  such 
is  the  adhesive  powder  of  the  wet  sand  and  the  arrangement  of 
the  holding  bars,  that  it  almost  invariably  does.  The  cases  of  the 
breaking  of  moulds  because  the  sand  does  not  hold  are  not  frequent, 


CASTING  AND  FOUNDING. 


195 


and  the  main  loss  of  moulds  comes  from  the  breaking  of  the  flasks, 
which  sometimes  give  way  when  the  metal  is  being  poured  in, 
owing  to  the  great  weight  of  metal  and  sand  combined,  which  the 
flask  is  not  strong  enough  to  sustain.  This  occurs  mainly  in  large 
castings,  and  naturally  the  losses  are  very  serious,  it  being  often¬ 
times  very  difficult  to  recover  the  molten  metal,  which  becomes 
mixed  with  the  sand,  and  get  it  in  condition  for  casting  again. 
The  casting  being  generally  large,  the  losses  of  this  character  are 
mostly  heavy  ones. 

Moulds  have  to  be  broken  sometimes  because  of  the  impossibility 
of  removing  the  pattern  without  doing  so,  owing  to  the  bad  pattern¬ 
making,  and  in  this  case  both  the  mould  and  the  pattern  are  a  loss 
and  sometimes  a  very  expensive  one. 

The  green  sand  moulds  are  broken  up  after  they  have  been  used 
once,  and  most  of  the  dry  sand  moulds  are  broken  up  also,  and  if 
further  castings  are  wanted  new  moulds  are  prepared.  When  a 
number  of  castings  of  the  same  character  or  description  are  wanted, 
and  the  casting  is  a  small  one,  it  is  done  by  the  gate  system.  In 
other  words  a  number  of  patterns  are  prepared  and  joined  together 
by  a  little  bar  extending  one  from  the  other,  and  the  moulds  are 
made  from  this  gate  pattern.. 

The  rest  of  the  operation  is  the  same  as  any  casting,  and  the 
articles  are  secured  in  gate  or  joined  together  at  a  certain  point  by 
a  bar  or  bars  which  can  be  easily  broken,  and  the  rough  ends 
finished  off,  leaving  the  articles  just  as  they  are  wanted.  The 
advantage  of  this  method  is  that  a  larger  number  of  small  articles 
can  be  secured  by  one  gate  casting  which  otherwise  would  have  to 
be  cast  separately  at  the  expenditure  of  much  additional  labor  and 
time. 

The  patterns  for  this  gate-casting  system  are  made  separately, 
but  with  the  little  bars  projecting  out  in  such  a  manner  as  to  form 
a  continuous  bar  or  connection  in  the  casting.  This  method  of 
work  is  very  useful  in  the  casting  of  small  articles,  and  is  practised 
to  a  great  extent  by  the  gray  iron  foundries.  The  moulds  and 
flasks  for  this  gate  casting  are  made  in  exactly  the  same  manner  as 
for  other  castings. 


196 


TUE  METAL  WORKER’S  IIANDY-BOOK. 


The  flasks  for  the  different  moulds  are,  according  to  circum¬ 
stances,  made  in  three  or  four  parts  to  conform  to  the  joints  of  the 
mould,  which  in  turn  is  based  upon  the  character  of  the  pattern. 
The  joints  in  the  mould,  and  consequently  in  the  flask,  are  for  the 
purpose  of  removing  the  various  parts  so  as  to  get  the  pattern  out, 
and  the  pattern  itself  has  to  be  jointed,  in  order  that  it  may  be 
taken  out  properly.  There  are  frequently  more  joints  in  the  flask 
and  mould  than  in  the  pattern.  The  top  of  the  flask,  which  is 
always  a  removable  part,  is  called  the  cope.  This  cope  is  invari¬ 
ably  gaggered  ;  that  is,  it  has  the  bars  and  hooks  above  mentioned 
extending  from  its  inner  surface  to  hold  the  sand  in  place.  The 
bottom  of  the  mould  is  called  the  nowel,  and  the  pieces,  parts,  or 
sides  between  the  cope  and  nowel  are  termed  the  cheeks.  Accord¬ 
ing  to  the  style  of  the  pattern  the  cheeks  are  few  or  many;  that  is, 
they  have  few  joints  or  a  good  many.  The  cope  is  of  course  always 
removable,  and  the  cheeks  are  also,  to  get  the  patterns  out.  In 
very  large  castings  the  foundry  floor,  which  is  always  made  of 
moulding  sand,  is  used  for  the  nowel,  and  the  cope  and  cheeks  are 
constructed  in  the  flask  as  usual. 

Foundry  Flasks. — Fig.  4  (i)  is  a  plan  of  the  section  view  ;  Fig. 
4  (2)  showing  a  very  serviceable  and  useful  style  of  cast-iron  flasks 
used  in  some  foundries.  They  are  made  from  band-pulley  patterns, 
and  have  a  flange  cast  on  each  edge.  No  bars  are  cast  in  them. 
Two  holes,  A  A,  are  drilled  and  countersunk  in  each  flange  for  the 
wrought  guide-pins  B  (one  shown  bolted  in  position  at  C).  By 
this  arrangement  a  drag  or  cope  of  any  depth  can  be  made  by 
simply  placing  the  pieces  on  top  of  each  other,  and  fastening 
together  with  bolts  and  clamps  made  for  the  purpose.  Crossbars 
can  be  fitted  in  the  cope  to  suit  the  work.  In  a  certain  foundry 
they  have  also  a  large  number  of  square  and  oblong  flasks  made  in 
the  same  order  as  shown  in  broken  plan,  Fig.  4  (3).  These  flasks 
are  in  constant  use.  The  drags  of  the  smaller  sizes  are  turned 
over  on  a  level  sand  bed  without  any  danger  of  their  dropping  out. 
Bottom  boards  are  used  on  the  larger  ones,  unless  the  work  is  of 
such  a  character  as  to  bed  in.  The  drags,  of  green  and  dry  sand 


CASTING  AND  FOUNDING. 


197 


mould,  four  and  five  deep,  are  made  in  a  comparatively  short  time 
by  having  these  sections  to  clamp  together. 

Fig.  4  (4)  is  a  broken  plan  of  another  style  of  square  and  oblong 
cast-iron  flasks,  which  are  handy  in  a  foundry  for  general  or  special 
work.  The  lugs  D  are  cast  plain  and  drilled  by  a  template,  and 
wrought-iron  guide-pins  bolted  in  for  the  cope.  Section  Fig.  4  (5) 
is  on  a  line  through  Fig.  4  (4)  from  E  to  E  (without  showing  the 
lug  D~).  The  joint  edge  E  has  a  strengthening  strip  cast  on  it, 
and  the  handles  G  are  made  by  placing  cores  rammed  up  in  core¬ 
box,  Fig.  4  (6),  against  the  end  of  the  pattern  when  moulding  the 
flask. 

Fig.  4  (7)  is  the  plan  of  the  drag  of  a  flask  used  more  especially 
on  moulding  machines,  but  which  are  successfully  and  profitably 
used  on  the  floor  in  some  foundries.  These  flasks  are  made  with 
the  sides  and  ends  straight  or  tapered,  as  may  be  required.  As  the 
lugs  H H  fit  over  pins  on  the  moulding  machine,  which  are  the 
counterpart  of  the  pins  cast  on  the  cope,  it  is  necessary  to  have  the 
inside  of  the  lugs  smooth,  and  as  near  the  same  size  as  possible.  For 
this  purpose  the  cast-iron  clamp,  Fig.  4  (8),  is  made  and  planed 
upon  the  sides  and  inside  of  the  ends  at  /.  The  ends  of  these 
clamps  or  formers  at  I  ought  to  be  wide,  and  long  enough  to 
extend  into  the  sand  beyond  the  lugs,  so  as  to  prevent  a  rough 
place  or  fins  on  the  points  at  J,  which  would  prevent  the  flask 
fitting  nicely  on  the  guides  of  the  moulding  machine,  or  the  cope- 
pins  working  in  the  drag.  The  plan  is  very  simple.  The  flask 
pattern  is  of  cast-iron,  and  when  moulding  it  the  clamp  is  set  in  the 
lugs,  and  rammed  up  with  the  pattern,  and  left  in  the  mould  when 
the  pattern  is  drawn  out  on  the  plan  of  any  chill. 

Fig.  4  (9)  is  a  plan  view  of  the  cope  of  this  type  of  flask.  Fig. 
4  (10)  is  an  end  elevation  of  Fig.  4  (9),  and  Fig.  4  (11)  is  a  cross- 
section  of  the  same  broken  off  at  K.  These  views  show  the  style 
of  cast-iron  formers  or  chills  that  are  used  to  cast  the  guide-pins  in ; 
these  pins  fit  into  recesses  in  the  moulding  machine,  and  must  be 
very  exact  to  prevent  shifting  on  the  machine,  or  when  the  cope- 
sand  drags  are  closed  together.  It  will  be  noticed  that  the  chill 
extends  beyond  the  pin  at  L  L ,  and  is  also  a  little  deeper  at  MM, 


198 


THE  METAL  WORKER’S  HANDY-BOOK. 


Figs.  4  (io)  and  4  (11).  This  prevents  the  fins  and  ragged  edges 
spoken  of  in  connection  with  the  lugs,  Fig.  4  (9). 

These  pins  and  lugs  are  made  heavy  and  strong,  and  as  the 


F'g  4- 


flasks  are  cast  of  soft  foundry  iron,  the  bearing  or  working  parts 
of  the  pins  and  lugs  have  a  smooth  surface ;  they  fit  together  very 
nicely,  and  do  not  wear,  and  are  not  easily  broken  off.  Wooden 


CASTING  AND  FOUNDING. 


199 


handles  JV  JV  are  bolted  to  the  flasks,  and  if  desired  for  the  class 
of  work  to  be  made  in  them,  strengthening  strips  or  bars  can  be 
cast  across  the  bottom  of  the  drags,  and  crossbars  of  any  style  cast 
in  the  copes  (this  can  also  be  done  in  Figs.  4  (3)  and  4  (4).  Flasks 
of  this  pattern  made  for  a  moulding  machine  have  been  used  con¬ 
stantly  on  the  floor  for  other  work,  and  as  they  are  interchangeable 
there  is  no  danger  of  getting  the  flasks  mixed.  Fig.  4  (12)  is  one 
style  of  end  for  a  heavier  class  of  cast-iron  flasks.  The  braces  O  O 
extend  from  the  height  of  the  trunnion-hole  P,  and  taper  off  to  the 
ends;  Q  Q  are  strengthening  brackets  for  the  flanges  P  R,  Fig.  4 
(13)  being  a  cross-section  from  P.  It  is  not  always  that  both  these 
flanges  are  cast  oh,  sometimes  only  on  the  joint  edge  of  the  flask, 
and  often,  when  the  centre-rib  brace  is  used,  no  flanges  are  made 
except  at  the  ends  for  bolting  to  wooden  sides.  The  holes  £  5  are 
for  bolting  to  the  ends  of  heavy  iron  sides,  Fig.  4  (14),  which  have 
a  flange  all  around  the  edge,  and  holes,  at  T  T,  for  bolting  iron 
crossbars  shown  in  side  and  edge  views,  Fig.  4  (15  and  16).  The 
various  shapes  at  V  V  will  be  understood  by  moulders  as  being  made 
to  suit,  and  intended  to  fit,  corresponding  shapes  in  the  pattern ; 
the  holes  IV  W  are  cast  in  to  make  the  bars  lighter,  and  as  many 
can  be  made  as  desirable,  so  that  it  does  not  affect  the  strength  of 
the  bar. 

Fig.  4  (17)  shows  a  style  of  trunnion  made  of  wrought-iron  for 
lifting  and  swinging  heavy  flasks.  The  trunnion  is  put  through  the 
hole  P,  and  fastened  by  driving  the  key,  Fig.  4  (18),  into  the  slot 
near  the  end  of  the  trunnion.  This  leaves  a  projection  on  the 
inside  of  the  flask,  and  is  not  near  so  convenient  in  any  way 
(whether  the  flask  is  round  or  square)  as  to  cast  a  good  strong 
trunnion  on  the  flask  seen  at  Fig.  4  (19);  or  the  end  of  the  trunnion 
X  can  be  of  wrought-iron  and  cast  fast  in  the  flask. 

Y  Y,  Fig.  4  (14),  is  another  style  of  handles  or  loops  for  heavy 
flasks.  These  are  better  made  of  wrought-iron,  and  cast  fast  or 
bolted  in  the  sides  of  the  flasks ;  they  can  be  put  in  straight  or  at 
any  angle  to  suit.  For  flasks  of  medium  weight  a  good  strong 
handle  of  this  style  can  be  made  in  a  core,  as  at  Fig.  4  (20),  and 
cast  on  the  sides  of  the  flask.  Fig.  4  (6  and  20)  are  section  views 


200 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


of  the  straight  and  loop  style  of  handle  rammed  up  in  the  core-box, 
showing  them  before  the  core-box  is  turned  over  to  remove  the 
handle  patterns.  In  the  drawings  the  core-boxes  are  shown  deeper 
than  is  really  necessary  (Robert  E.  Masters,  in  “The  Western 
Machinist.  ”) 

To  Mould  Lace,  etc.,  in  Cast-iron. — Mr.  Outerbridge  has  suc¬ 
ceeded  in  moulding  fine  lace  in  cast-iron,  the  impression  showing 
the  most  delicate  lines  of  the  pattern.  The  lace  to  be  moulded  must 
first  be  carbonized.  In  place  of  lace  other  fine  tissues,  embroid¬ 
ered  ornamentations  upon  stuffs,  leaves,  grasses,  etc.,  may  also  be 
moulded,  previous  carbonization  being,  however,  always  required. 
The  process  is  as  follows  :  The  respective  articles  are  laid  flat  upon 
a  layer  of  pulverized  coal  upon  the  bottom  of  a  cast-iron  box ; 
another  layer  of  pulverized  coal  is  then  sifted  upon  them. 
Another  layer  of  patterns  may  be  laid  upon  this,  succeeded  by 
another  layer  of  pulverized  coal,  and  so  on  until  the  box  is  full. 
The  box  being  closed  with  a  well-fitting  lid  it  is  placed  in  a  furnace 
and  heated,  at  first  slowly  to  expel  moisture  and  gases,  until  the 
blue  flames  disappear.  The  heat  is  then  increased  to  a  white  heat 
and  continued  for  at  least  two  hours.  The  box  is  then  taken  from 
the  furnace  and  allowed  to  cool  off  gradually,  when  the  tissue  is 
taken  out  and  tested  in  a  gas  flame.  If  carbonization  is  complete 
the  tissue  suffers  no  change  and  is  ready  for  casting.  It  shows 
great  pliancy,  the  same  as  is  observed  in  the  carbon  threads  of  in¬ 
candescent  lamps.  In  the  first  experiments  a  piece  of  lace  carbon¬ 
ized  in  the  manner  above  described  was  laid  upon  moulding  sand, 
the  ends  being  allowed  to  project  over  the  edges  of  the  flask  to 
insure  against  displacement.  The  fluid  iron  being  poured  in,  the 
carbonized  lace  fixed  itself  firmly  to  the  sand,  and  after  casting 
could  without  difficulty  be  detached  from  the  iron.  Thus  several 
castings  can  be  obtained  from  one  pattern.  The  impressions  are 
extraordinarily  fine  and  delicate,  and  could  formerly  only  be 
obtained  by  galvanic  deposition.  It  does  not  matter  whether  soft 
gray  foundry-pig  or  white  pig  is  used. 

The  success  of  the  castings  must  be  chiefly  attributed  to  the 
peculiarity  of  iron  of  possessing  under  certain  circumstances  a 


CASTING  AND  FOUNDING. 


201 


tendency  of  absorbing  carbon.  In  flowing  over  the  carbonized 
lace  the  liquid  iron  evidently  combines  with  the  carbon  of  the 
pattern,  and  very  likely  would  completely  absorb  the  tissue  if  it 
did  not  congeal  so  rapidly.  Something  similar  may  be  observed 
with  mercury.  The  latter  when  poured  upon  a  table  runs  about  in 
globules  without  moistening  the  table,  unlike  water.  But  when 
poured  upon  a  zinc  plate  it  does  not  run  off  in  globules,  but  in¬ 
stantly  combines  with  the  zinc,  moistening  it  like  water.  It  is, 
therefore,  evident  that  if  another  metal,  such  as  brass  or  zinc, 
were  poured  upon  carbonized  articles,  such  sharp  impressions  could 
not  be  obtained. 

Cores  in  Heavy  Castings.— When  cores  run  through  heavy  bodies 
of  iron,  the  hot  liquid  raises  the  fusible  element  of  the  sand  to 
such  a  high  temperature  that  the  grains  fuse  together,  so  that  when 
the  casting  cleaner  tries  to  get  the  core  out  lie  finds  it  almost  as 
hard  as  the  iron.  A  good  thing  to  prevent  this  fusing  of  the  sand 
is  to  mix  some  sea-coal  or  blacking  in  it,  and  to  give  the  surface 
of  the  core  a  good  body  of  black  lead  or  plumbago  blacking. 
This  outside  coat  of  blacking  will  prevent  the  liquid  iron  from 
eating  into  the  surface  of  the  core  sand,  and  the  sea-coal  or  black¬ 
ing  mixed  in  the  sand  burns  away  and  passes  off  in  the  form  of 
gas,  leaving  a  porous  body  between  the  grains  of  sand,  which 
assists  in  preventing  its  fusion. 

In  putting  rods  in  such  cores  as  are  subjected  to  a  high  tempera¬ 
ture,  it  is  a  good  plan  to  coat  them  with  two  or  three  coats  of  flour- 
paste  and  dry  them  in  an  oven  as  it  is  put  on  ;  for  by  doing  this 
the  dried  paste  burns  off  from  the  rod  and  leaves  it  free  to  come 
out  of  the  casting. 

Core  for  Difficult  Castings. — The  following  are  instructions  for 
a  composition  for  cores  that  may  be  required  for  difficult  jobs, 
where  it  would  be  extremely  expensive  to  make  a  core-box  for 
them :  Make  a  pattern  (of  any  material  that  will  stand  moulding 
from)  like  the  core  required.  Take  a  mould  from  the  same  in  the 
sand,  in  the  ordinary  way,  place  strengthening  wires  from  point  to 
point,  centrally,  gate  and  close  your  flask.  Then  make  a  compo¬ 
sition  of  2  parts  brickdust  and  x  of  plaster  of  Paris ;  mix  with 


202 


TITE  METAL  WORKER’S  HANDY-BOOK. 


water  and  cast.  Take  it  out  when  set,  dry  it  and  place  it  in  the 
mould  warm,  so  that  there  may  be  no  cold  air  in  it. 

Casting  Without  Core. — This  mode  of  casting  would,  no  doubt, 
be  used  more  if  it  were  not  connected  with  a  peculiar  disadvantage. 
Casting  without  core  is  executed  by  pouring  the  fluid  metal  (zinc, 
tin,  lead  or  alloys  of  these  metals)  into  a  mould  generally  of  brass 


with  a  comparatively  large  gate,  whereby  the  gate  must  of  course 
be  kept  uppermost,  just  the  reverse  of  the  position  shown  in  the 
illustration,  Fig.  5.  The  mould  b  entirely  filled  with  liquid  metal 
is  then  more  or  less  quickly  inverted,  so  that  it  comes  into  the 
position  shown  in  the  illustration.  By  not  allowing  time  for  com¬ 
plete  congelation  the  larger  portion  of  the  metal  poured  in  will 


CASTING  AND  FOUNDING. 


203 


run  out,  whilst  a  crust  c  of  more  or  less  thickness  remains  in  the 
mould  and  forms  a  casting  useful  for  many  industrial  purposes. 

To  obtain  solid  castings  free  from  blowholes  the  metal  must 
stand  under  a  certain  pressure  which  is  also  required  for  other 
castings.  For  this  purpose  a  “dead-head  ”  (riser  or  sullage  piece) 
is  used,  and  as  the  dead-head  is  also  hollow  after  inverting  the 
mould,  this  portion  of  the  casting  is  called  the  “  funnel.”  In  the 
illustration  a  small  bust  A  is  given  as  an  example  of  casting  with¬ 
out  a  core  ;  the  lower  portion  of  the  finished  bust  is  indicated  by 
the  curved  line  d ;  B  is  the  dead-head  or  funnel  which  simply 
serves  for  making  the  metal  in  A  compact.  After  removing  the 
casting  from  the  mould  the  dead-head  or  funnel  B  is  separated 
from  the  casting  by  sawing,  filing  or  other  suitable  mechanical 
treatment  along  the  edge  of  d.  The  metals  chiefly  used  for  casting 
without  a  core  possess,  however,  the  peculiarity  of  being  worked 
with  difficulty,  especially  zinc  and  many  zinc  alloys,  fouling  the 
saws  and  files  so  that  the  separation  of  the  dead-head  from  the 
casting  becomes  a  difficult  matter.  This  is  the  chief  reason  why 
casting  without  core  is  comparatively  little  in  use. 

The  necessity  of  removing  the  dead-head  or  funnel  by  sawing, 
filing,  etc.,  however,  is  entirely  done  away  with  by  working  in  the 
mould  b  along  the  edge  of  d  a  groove  e.  This  groove  is  filled  with 
a  material  which  is  a  bad  conductor  of  heat  but  will  stand  a  high 
temperature,  asbestos  being  especially  recommended  for  the  purpose. 
Now,  while  the  fluid  metal  when  poured  in  congeals  on  the 
metallic  walls  of  the  mould,  they  being  good  conductors  of  heat, 
congelation  does  not  take  place  along  the  line  of  the  asbestos,  the 
metal  poured  in  remaining  fluid,  or  at  least  much  more  fluid  on 
this  point  than  on  other  places  of  the  mould.  By  now  inverting 
the  mould  the  strip  i  lying  opposite  to  the  groove  e  filled  with 
asbestos  runs  out  together  with  the  metal  filling  the  mould,  and 
when  taking  the  mould  apart  the  dead -head  or  funnel  B  will  be 
found  separated  from  the  actual  casting,  or  connected  with  it  only 
by  a  very  thin  film  which  can  readily  be  severed. 

Casting  Brass-nuts  o?i  Screws. — Polish  the  screw,  make  a  mould 
on  it,  with  a  gate  or  runner  at  the  end  when  the  mould  is  hori- 


204 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


zontal,  x  inch  in  diameter,  5  inches  high,  scoop  out  the  top  3 
inches  diameter  levelled  down  to  1  inch ;  second,  make  the  gate 
or  runner  on  the  top  of  screw  y2  inch  diameter,  same  height  as 
the  other.  Take  a  pricker  and  prick  from  the  top  of  the  mould  to 
the  pattern  nut  about  a  dozen  holes,  after  which  draw  diamonds 
with  the  wire  from  these  holes  to  the  sides  of  t'he  mould  on  the 
top.  Now  part  the  mould,  draw  the  nut  and  screw,  cut  the  gates, 
making  the  one  at  the  end  of  nut  same  as  the  down  one,  one  inch 
in  diameter ;  take  the  screw,  smoke  it  over  a  gas  flame,  turning  it 
round,  pouring  a  little  oil  on  it;  continue  heating  till  the  oil  begins 
to  boil.  At  this  stage  take  a  little  dry  of  the  parting-sand,  which 
is  used  to  part  the  mould,  sprinkle  this  all  round  on  the  top  of  the 
oil,  heat  now  as  before  to  dull  red  and  proceed  as  before.  Remelt 
the  metal,  take  3  lbs.  of  old  waste  handles  free  from  iron,  add  to 
this  9  lbs.  of  copper,  melt  both,  and  when  ready  for  casting  add 
y2  lb.  of  zinc  or  spelter,  allow  it  to  remain  in  the  fire  ten  minutes, 
take  it  out,  add  y2  lb.  of  block  tin  and  y  lb.  of  lead ;  stir  the 
whole  well  up.  The  screw  is  now  red  and  in  the  mould ;  rush  the 
metal  in  quickly  at  the  gate  1  inch  diameter ;  be  sure  the  metal  is 
hot  and  it  will  rise  at  the  other  gate  to  the  top  of  the  mould.  Be 
careful  at  this  stage.  To  take  the  nut  off  do  not  heat  it ;  dress  it 
as  before ;  hammer  it  cold,  heat  it — now  hold  the  screw  upright, 
pour  on  oil  at  the  top  of  the  nut,  allow  it  to  cool,  catch  the  nut  in 
vice,  apply  a  lever  to  the  square  at  end  of  screw  and  turn  it 
around. 

Casting  071  to  other  Metals. — It  is  occasionally  desired  to  unite 
other  metals  by  means  of  cast-iron,  or  to  fix  ornamental  castings  on 
to  light  work  made  of  wrought-iron  or  steel.  One  well-known 
application  of  this  process  is  Moline’s  invention  for  the  combina¬ 
tion  of  wrought  and  cast-iron  in  the  manufacture  of  window-frames. 
The  sash-bars  are  formed  of  wrought-iron,  rolled  of  any  light  and 
convenient  section,  suited  to  receive  glass:  these  bars  are  united 
by  ornamental  cast-iron  bosses. 

An  iron  pattern  is  first  made,  from  which  a  sand  mould  is  ob¬ 
tained  ;  the  wrought-iron  bars  are  cut  to  the  required  lengths  and 
placed  in  the  mould  with  their  ends  nearly  touching ;  over  these 


CASTING  AND  FOUNDING. 


205 


ends  the  mould  of  the  boss  is  placed,  which  must  be  sufficiently 
large  to  cover  them  so  that,  when  cast  on,  the  bosses  shall  firmly 
unite  the  wrought-iron  bars.  These  windows  can  be  readily  made 
of  any  usual  size  or  shape,  and  are  easily  fixed  They  are  light  in 
appearance,  and  combine  the  strength  of  wrought-iron  with  the 
ornamental  character,  which  can  be  readily  obtained  by  the  addi¬ 
tion  of  cast-iron  flowers,  scrolls,  armorial  bearings  and  other 
Ornaments. 

For  ornamenting  wrought-iron  railings,  two  ways  of  applying 
cast-iron  may  be  mentioned.  Either  the  wrought-iron  bars  may  be 
placed  in  the  moulds  and  the  ornaments  cast  round  their  ends,  or 
the  ornaments  may  be  cast  in  green  sand  moulds,  cored  out  to  fit 
wrought-iron  bars,  on  to  which  they  are  afterwards  fixed  by  an  alloy 
of  zinc  and  lead.  Lead  alone  is  to  be  avoided,  as  it  sets  up  a 
galvanic  action  and  assists  the  formation  of  rust. 

In  designing  cast-iron  railings  it  will  be  well  to  adopt  outlines  in 
which  the  metal  will  not  be  unfairly  strained,  by  the  union  of  very 
light  and  heavy  pieces  in  the  same  casting.  Discard  all  very  fine 
ornamental  work  for  streets  where  there  is  much  traffic,  as  accident 
or  mischief  will  very  shortly  spoil  the  beauty  of  the  work  which 
cannot  be  repaired.  Ornamental  cast-iron  work  of  a  fine  intricate 
character  is  only  in  place  where  it  can  be  seen  to  advantage,  and  is 
not  exposed  to  violence. 

If  cast-iron  chill-moulds  are  used  for  the  ornamental  castings, 
the  ornaments  will  naturally  be  rather  brittle ,  in  most  cases  this 
will  be  found  of  little  consequence,  but  where  it  is  desired  to  avoid 
brittleness,  the  work  can  be  placed  in  an  annealing  oven,  when  the 
cast-iron  will  be  made  into  malleable  cast-iron  without  prejudicially 
affecting  the  wrought-iron  if  any  is  used  in  conjunction  with  the 
cast-iron,  as  is  frequently  done. 

Ornamenting  Wrought-iron  by  Burning  on. — Burning  on  is  occa¬ 
sionally  practised  for  the  purpose  of  ornamenting  wrought-iron 
with  scrolls,  volutes,  or  twisted  forms.  Loam  moulds  are  made, 
and,  when  thoroughly  dried,  are  applied  to  that  portion  of  the 
wrought-iron  which  it  is  wished  to  burn  on  to ;  cast-iron  is  then 
poured  through  the  moulds  until  the  wrought-iron  is  brought  to  a 


206 


THE  METAL  WORKER’S  HANDY- BOOK. 


welding  heat  ;  pouring  is  then  ceased,  and  the  cast-iron,  when 
cooled  down,  is  found  firmly  affixed  to  the  wrought-iron. 

For  ornamental  cast-iron  railings  which  are  designed  with  com¬ 
paratively  heavy  pilasters  and  bars,  having  the  intervals  between 
them  filled  in  with  light  ornamental  work,  the  two  should  not  be 
cast  at  one  and  the  same  time,  otherwise  the  light  work  will  be 
almost  certain  to  break  away  from  the  heavy,  owing  to  the  unequal 
contraction  in  cooling.  The  ornamental  work  should  be  cast  first, 
of  fine,  soft,  fluid  iron,  and  be  provided  with  small-fitting  pieces  or 
lugs  at  convenient  points  for  fixing  to  the  heavy  bars  or  up¬ 
rights.  Coat  these  lugs  on  the  fine  work  with  clay  and  black-wash, 
place  in  a  sand  mould  and  cast  the  heavy  work  round  it.  By  so 
doing  the  iron  will  not  be  liable  to  fracture  from  unequal  contrac¬ 
tion  and  expansion. 

To  Repair  Castings  by  Burning  on. — A  piece  of  machine  framing, 
the  necks  of  rolls  or  a  standard  which  has  been  broken  or  found 
defective  may  be  repaired  as  follows :  First  cut  away  the  defective 
parts  down  to  the  sound  metal ;  build  a  coke-fire  round  the  part 
of  the  casting  which  is  to  be  repaired  until  it  is  brought  to  a  bright 
red-heat,  then  dust  over  the  surface  of  the  cut  metal  with  powdered 
glass  or  borax.  Then  apply  a  hollow  loam  mould  of  the  desired 
part  to  the  casting,  properly  secured  in  position  and  provided  with 
a  hole  for  the  exit  of  the  metal.  Pour  very  hot  liquid  cast-iron 
into  the  mould  and  allow  it  to  flow  away  until  the  cut  surface  of 
the  original  metal  of  the  casting  can  be  felt  with  an  iron  bar  to 
have  become  soft  and  pasty  by  contact  with  the  hot  liquid  iron. 
Then  stop  the  exit  hole  and  allow  the  metal  in  the  mould  to  set. 
If  the  operation  has  been  properly  performed  the  casting  should, 
when  struck,  ring  with  the  same  sound  as  a  single  good  casting, 
thus  showing  that  the  old  and  new  metal  are  perfectly  united. 

To  Fill  up  Holes  in  Castings. — Holes  occasionally  occur  on  the 
surface  of  a  casting,  which,  although  not  of  sufficient  importance 
to  make  it  advisable  to  reject  or  break  up  the  casting,  are  unsightly. 
Liquid  cast-iron  may  be  poured  into  such  holes,  the  superfluous 
metal  being  removed  by  an  iron  straight-edge.  It  is  usually  pre¬ 
ferred,  however,  to  fill  up  these  cavities  with  an  alloy  having  a 


CASTING  AND  FOUNDING. 


207 


similar  appearance  to  the  cast-iron,  but  being  much  more  fusible. 
One  such  alloy  consists  of  antimony,  69  parts  by  weight ;  copper, 
16;  tin,  2,  melted  together;  to  which  add  afterwards,  lead,  13 
parts  ;  another  is,  antimony,  65  parts  by  weight;  copper,  16;  lead, 
13;  prepared  in  the  same  way. 

Bell  Founding. — The  most  important  point  in  the  art  of  bell 
founding  is  the  proper  form  to  give  a  bell  to  obtain  the  desired 
tone,  which  is  also  dependent  on  the  metal  used.  In  a  bell  of  the 
usual  proportions  the  thickness  of  the  upper  or  thin  part  is  one- 
third  of  the  sound-bow,  or  thickest  part.  As  to  the  thickness  of 
the  sound-bow  itself,  which  is  often  spoken  of  simply  as  the  thick¬ 
ness  of  the  bell,  large  bells  of  a  peal  are  sometimes  made  as  thin 
as  of  the  diameter,  and  the  small  ones  as  thick  as  T\j  of  the 
diameter;  the  most  effective  proportion  is  from  TD2  to  TD5. 

In  casting  peals  of  bells  it  is  necessary  to  take  rather  a  wider 
range,  in  order  to  prevent  the  treble  being  so  small  and  weak  as  to 
be  overpowered  by  the  tenor,  though  care  must  be  taken  not  to  run 
into  the  opposite  extreme  and  make  the  large  bells  too  thin.  In 
calculating  the  sizes  of  bells  to  produce  particular  notes,  and  as¬ 
suming  that  eight  bells  are  made  of  similar  material,  and  their 
sections  exactly  similar  figures,  in  the  mathematical  sense,  they 
will  sound  the  eight  notes  of  the  diatonic  scale,  if  all  their  dimen¬ 
sions  are  in  these  proportions:  60,  53^,  48,  45,  40,  36,  32,  30, 
which  are  merely  convenient  figures  for  representing  the  inverse 
proportions  of  the  times  of  vibration  belonging  to  the  eight  notes 
of  the  scale.  So  that  if  it  is  required  to  make  a  bell  a  fifth  above 
a  given  one,  it  must  be  2/s  of  the  size  in  every  dimension,  unless  it 
is  intended  to  vary  the  proportion  of  thickness  to  diameter,  for  the 
same  rule  then  no  longer  holds,  as  a  thinner  bell  will  give  the  same 
note  with  a  less  diameter. 

The  reason  is  that  according  to  the  law  of  vibrating  plates  or 

thickness 

springs,  the  time  of  vibration  of  similar  bells  varies  as  2. 

When  the  bells  are  also  completely  similar  solids,  the  thickness 
itself  varies  as  the  diameter,  and  then  the  time  of  vibration  may 
be  said  simply  to  vary  inversely  as  the  diameter. 


208 


THE  METAL  WORKER’S  HANDY-BOOK. 


The  weights  of  bells  of  similar  figures  vary  as  the  cubes  of  their 
diameters,  and  may  be  nearly  enough  represented  by  the  figures 
216,  152,  no,  91,  64,  46,  33,  27.  The  exact  tune  of  a  set  of 
bells  as  they  come  out  of  the  moulds  is  a  secondary  consideration 
to  their  tone  or  quality  of  sound,  because  the  notes  can  be  altered 
a  little  either  way  by  cutting,  but  the  quality  of  the  tone  will 
remain  the  same  forever,  except  that  it  grows  louder  for  the  first  two 
or  three  years  that  the  bell  is  used,  probably  from  the  particles 
arranging  themselves  more  completely  in  a  crystalline  order  under 
the  hammering,  as  is  well  known  to  take  place. 

The  designing  of  bells  is  regulated  by  certain  fixed  rules,  derived 
from  experience,  and  which  are  handed  down  from  one  generation 
of  bell  founders  to  another ;  some  makers  have  their  own  peculiar 
mixtures  of  metal  and  design  of  bell,  to  which  they  attach  par¬ 
ticular  importance  and  secrecy,  but  it  is  doubtful  whether  any  real 
advantage  has  been  attained,  either  in  tone  or  durability,  by  any  of 
the  secret  processes  as  compared  with  bells  carefully  designed  and 
cast  with  proper  precautions,  and  a  thoroughly  good  metal,  on  the 
ordinary  plan. 

Small  bells  are  generally  moulded  in  sand  from  a  metal  or 
wooden  pattern,  and  the  sand-mould  is  dried  in  a  stove. 

Large  bells  are  moulded  in  loam.  The  core  is  built  in  brick 
on  an  iron  platform,  which  must  have  nugs  in  case  the  mould  is 
made  above  ground.  This  brick  core  is  covered  with  ^  inch  or 
1  inch  thick  of  hair-loam,  and  the  last  surface  washing  is  given  by 
finely  ground  composition  of  clay  and  brickdust.  This  latter  is 
mixed  with  an  extract  of  horse-dung,  to  which  is  added  a  little 
sal-ammoniac.  Upon  the  core  the  “thickness”  is  laid  in  loam- 
sand,  but  the  thickness  is  again  washed  with  fine  clay  to  give  it  a 
smooth  surface.  Ornaments  which  have  been  previously  moulded, 
either  in  wax,  wood  or  metal,  are  now  attached  by  means  of  wax, 
glue  or  any  other  kind  of  cement.  If  the  ornaments  are  of  such 
a  nature  as  to  prevent  the  lifting  of  the  cope  without  them,  for  the 
cope  cannot  be  divided,  the  ornaments  are  fastened  to  the  thick¬ 
ness  by  tallow,  or  a  mixture  of  tallow  and  wax.  A  little  heat  given 
to  the  mould  will  melt  the  tallow,  after  which  the  ornaments  ad- 


CASTING  AND  FOUNDING. 


209 


here  to  the  cope,  from  which  they  may  be  removed  when  the  cope 
is  lifted  off  the  core.  The  thickness  must  be  well  polished  ;  and, 
as  coal  cannot  be  used  for  parting,  the  whole  is  slightly  dusted 
over  with  wood  ashes.  The  parting  between  the  core  and  the 
thickness  is  also  made  with  ashes.  The  cope  is  laid  on  at  first  by 
means  of  a  paint  brush,  the  paint  consisting  of  clay  and  ground 
bricks,  made  thin  by  horse-water.  This  coating  is  to  be  thin  and 
fine  ;  upon  it  hair-loam  and  finally  straw  loam  is  laid. 

The  crown  of  the  bell  is  moulded  over  a  wood  pattern,  after  the 
spindle  is  removed.  The  iron  or  steel  staple  for  the  hammer  is  set 
in  the  core,  into  the  hollow  left  by  the  spindle.  It  projects  into 
the  thickness,  so  as  to  be  cast  into  the  metal.  The  facing  of  the 
mould  ought  to  be  finished  when  the  cope  is  lifted  off.  Small  de¬ 
fects  may  occur,  and  are,  if  not  too  large,  left  as  they  are ;  the  ex¬ 
cess  of  metal  in  those  places  being  chiselled  off  after  the  bell  is 
cast.  All  that  can  be  done  in  polishing  the  facing  of  the  mould  is 
to  give  it  a  uniform  dusting  of  ashes.  When  the  mould  is  perfectly 
dry,  it  is  put  together  for  casting.  The  core  may  be  filled  with 
sand,  if  preferred,  but  there  is  no  harm  done  if  it  is  left  open,  for 
bell-metal  does  not  generate  much  gas,  and  there  is  no  danger  of 
an  explosion.  The  cope  is  in  some  measure  secured  by  iron,  but 
its  chief  security  is  in  the  strong  well-rammed  sand  of  the  pit. 
The  cast-gate  is  on  the  top  of  the  bell,  either  on  the  crown,  or  if 
the  latter  is  ornamented,  on  one  side  of  it.  Flow-gates  are  of  no 
use  here  ;  the  metal  must  be  clean  before  it  enters  the  mould ; 
there  is  no  danger  of  sullage. 

Casting  Aluminium  Bronze. — Aluminium  bronze  is  not  an  easy 
metal  to  cast  perfectly  until  the  moulder  is  familiar  with  its  peculi¬ 
arities,  The  great  enemies  of  steel  castings,  dissolved  oxides  and 
gases,  forming  blow-holes,  are  here  absent.  The  aluminium  re¬ 
moves  these  impurities  from  the  original  copper  and  by  its  presence 
afterwards  keeps  the  bronze  free  from  them.  The  obstacles  which 
afford  most  trouble  in  casting  aluminium  bronze  are  the  shrinkage 
in  setting  and  contraction  in  cooling.  These  two  factors  are 
extraordinarily  large,  and  must  be  met  by  provisions  made  in 
moulding. 

H 


210 


THE  METAL  WORKER'S  HAN  l)T  HOOK. 


A  plumbago  crucible  is  best  for  melting  the  bronze,  the  melt 
being  kept  covered  with  powdered  charcoal.  It  is  recommended 
to  coat  the  stirrers  and  skimmers  used  with  a  wash  made  of  plum¬ 
bago  and  a  little  fire-clay,  as  the  contact  of  the  bronze  with  bare  iron 
tools  cannot  but  injure  its  quality.  The  crucible  should  not  be 
kept  in  the  fire  any  longer  than  is  absolutely  required  to  bring  the 
bronze  to  proper  heat  for  casting.  As  the  metal  solidifies  rapidly, 
it  is  necessary  to  pour  it  quickly  and  to  make  the  gates  amply  large 
so  that  there  shall  be  no  “  freezing  ”  in  the  “  gates  ”  before  the  cast¬ 
ing  is  perfectly  fed.  To  obviate  the  shrinkage  as  much  as  possible, 
the  metal  is  allowed  to  enter  the  mould  at  a  temperature  not  higher 
than  will  admit  of  it  running  freely.  When  there  is  a  heavy  mass 
of  metal  in  the  shape  of  an  envelope  surrounding  a  core,  the  con¬ 
traction  upon  solidification  will  cause  the  metal  to  split  unless  the 
core  is  made  to  yield  equally  with  the  contraction.  Baked  sand- 
moulds  are  preferable  to  green  sand,  except  for  small  castings. 

One  of  the  chief  difficulties  met  with  in  the  casting  of  alumin¬ 
ium  bronze  is  to  avoid  oxidation  in  transferring  the  metal  from  the 
crucible  or  ladle  to  the  mould.  If  any  of  the  film  of  oxide  which 
floats  on  the  surface  should  get  into  the  casting  during  the  pouring, 
it  will  appear  there  like  so  much  dirt,  and  is  apt  to  cause  trouble. 
The  ordinary  “skim-gate”  will  prevent  this  in  the  case  of  small 
castings,  but  with  large  masses  the  metal  is  first  poured  into  a 
receiver,  which  is  connected  with  and  is  part  of  the  pouring  “gate,” 
but  is  prevented  from  entering  the  mould  by  means  of  a  plug,  which 
closes  up  the  mouth  of  the  “gate.”  To  illustrate  this  more  clearly, 
imagine  the  pouring  “gate”  shaped  like  a  funnel,  into  which  the 
metal  is  first  poured.  It  is  prevented  from  running  into  the  mould 
by  the  plug  already  mentioned.  As  soon  as  the  dirt  has  risen  to 
the  top  the  plug  is  withdrawn,  and  consequently  nothing  but  the 
clear  metal  at  the  bottom  enters  the  mould.  For  castings  over  50 
pounds  the  metal  is  poured  from  a  large  ladle  through  a  hole  in 
the  bottom.  Ample  facilities  should  be  made  for  the  escape  of 
gases. 

The  following  remarks  on  this  subject  are  extracted  from  a  paper 


CASTING  AND  FOUNDING. 


211 


on  “Casting  Aluminium-bronze  and  Other  Strong  Metals,”  by 
Thomas  D.  West : 

The  difficulties  which  beset  the  casting  of  aluminium-bronze  are 
in  some  respects  similar  to  those  which  were  encountered  in 
perfecting  methods  for  casting  steel.  There  is  much  small  work 
which  can  be  successfully  cast  by  methods  used  in  the  ordinary 
moulding  of  cast-iron,  but  in  peculiarly  proportioned  and  in  large 
bronze  castings  other  means,  and  extra  display  of  skill  and  judg¬ 
ment,  will  be  generally  required.  In  strong  metals  there  appears 
to  be  a  “  red  shortness  ”  or  degree  of  temperature  after  it  becomes 
solidified,  at  which  it  may  be  torn  apart  if  it  meets  a  very  little 
resistance  to  its  contraction,  and  the  separation  may  be  such  as 
cannot  be  detected  by  the  eye,  but  will  be  made  known  only  when 
pressure  is  put  upon  the  casting.  To  overcome  this  evil  and  to 
make  allowances  for  sufficient  freedom  in  contraction  much  judg¬ 
ment  will  often  be  required,  and  different  modes  must  be  adopted 
to  suit  varying  conditions.  One  factor  often  met  with  is  that  of 
the  incompressibility  of  cores  or  parts  forming  the  interior  portions 
of  castings,  while  another  is  the  resistance  which  flanges,  etc.,  upon 
an  exterior  surface  oppose  to  freedom  of  contraction  of  the  mass. 
The  core  must  generally  be  “  rotten,”  and  of  a  yielding  character. 
This  is  obtained  by  using  rosin  in  coarse  sand,  and  filling  the  core 
as  full  of  cinders  and  large  vent-holes  as  possible,  and  by  not  using 
any  core  rods  of  iron.  The  rosin  would  cause  the  core  when  heated 
to  become  soft,  and  would  make  it  very  nearly  as  compressible  as  a 
“green-sand”  core  when  the  pressure  of  the  contraction  of  the 
metal  would  come  upon  it. 

By  means  of  dried  rosin  or  green-sand  cores  we  were  able  to  meet 
almost  any  difficulties  which  might  arise  in  ordinary  work  from  the 
evils  of  contraction,  so  far  as  cores  were  concerned.  For  large 
cylinders  or  castings  which  might  require  large  round  cores  which 
could  be  “  swept,”  a  hay  rope  wound  around  a  core  barrel  would 
often  prove  an  excellent  yielding  backing,  and  allow  freedom  for 
contraction  sufficient  to  insure  no  rents  or  invisible  strains  in  the 
body  of  the  casting.  To  provide  means  for  freedom  in  the  con¬ 
traction  of  exterior  portions  of  castings  which  may  be  supposed  to 


212 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


offer  resistance  sufficient  to  cause  an  injury,  different  methods  will 
have  to  be  employed  in  almost  every  new  form  of  such  patterns. 
It  may  be  that  conditions  will  permit  the  mould  to  be  of  a 
sufficiently  yielding  character,  and  again  it  may  be  necessary  to  dig 
away  portions  of  the  mould  or  loosen  bolts,  etc.,  as  soon  as  the 
liquid  metal  is  thought  to  have  solidified.  In  any  metal  there  may 
be  invisible  rents  or  strains  left  in  a  casting  through  tension,  when 
cooling,  sufficient  to  make  it  fragile  or  crack  of  its  own  accord,  and 
it  is  an  element  which  from  its  very  deceptive  nature  should  com¬ 
mand  the  closest  attention  of  all  interested  in  the  manufacture  of 
castings. 

Like  contraction,  the  element  of  shrinkage  is  often  found  seriously 
to  impede  the  attaining  of  perfect  castings  from  strong  metals.  In 
steel  castings  much  labor  has  to  be  expended  in  providing  risers 
sufficient  to  “feed  solid”  or  prevent  “draw-holes”  from  being 
formed,  and  in  casting  aluminium-bronze  a  similar  necessity  is 
found.  The  only  way  to  insure  against  the  evils  of  shrinkage  in 
this  metal  was  to  have  the  “risers”  larger  than  the  body  or  part  of 
the  castings  which  they  were  intended  to  “feed.”  The  feeder  or 
riser  being  the  largest  body,  it  will,  of  course,  remain  fluid  longer 
than  the  casting,  and,  as  in  cast-iron,  that  part  which  solidifies  first 
will  draw  from  the  nearest  uppermost  fluid  body,  and  thus  leave 
holes  in  the  part  which  remains  longest  fluid.  The  above  principle 
will  be  seen  to  be  effective  in  obtaining  the  end  sought.  It  is  to  be 
remembered  that  it  is  not  practicable  to  “churn”  this  bronze,  as  is 
done  with  cast-iron.  A  long  cast-iron  roll,  i  foot  in  diameter,  can 
by  means  of  a  feeder  5  inches  in  diameter,  and  a  ^-inch  wrought- 
iron  rod,  be  made  perfectly  sound  for  its  full  length.  To  cast  such 
a  solid  in  bronze,  the  feeding-head  should  be  at  least  as  large  as  the 
diameter  of  the  roll,  and  the  casting  moulded  about  one-quarter 
longer  than  the  length  of  roll  desired.  The  extra  length  would 
contain  the  shrinkage-hole,  and,  when  cut  off,  a  solid  casting  would 
be  left.  This  is  a  plan  often  practised  in  the  making  of  guns,  etc., 
in  cast-iron,  and  is  done  partly  to  insure  against  the  inability  of 
many  moulders  to  feed  solid,  and  to  save  that  labor.  A  method 
which  has  been  found  to  work  well  in  assisting  to  avoid  shrinkage 


CASTING  AND  FOUNDING. 


213 


in  ordinary  castings  in  aluminium-bronze  was  to  “gate”  a  mould 
so  that  it  could  be  filled  or  poured  as  quickly  as  possible,  and  to 
have  the  metal  as  dull  as  it  would  flow  to  warrant  a  full-run  casting. 
By  this  plan  very  disproportionate  castings  have  been  made  without 
feeders  on  the  heavier  parts,  and  upon  which  draw-  or  shrinkage- 
holes  would  surely  have  appeared  had  the  metal  been  poured  hot. 

The  metal  works  well  in  our  ordinary  moulding  sands,  and 
“peels”  extremely  well.  As  a  general  thing,  disproportionate 
castings  weighing  over  ioo  lbs.  are  best  made  in  “dry”  instead 
of  “green-sand  ”  moulds,  as  such  will  permit  of  cleaner  work  and 
a  duller  pouring  of  the  metal,  for  in  this  method  there  is  not  that 
dampness  which  is  given  off  from  a  green-sand  mould,  and  which  is 
so  liable  to  cause  “  cold  shots.”  When  the  position  of  the  casting 
work  will  permit,  many  forms  which  are  proportionate  in  thickness 
can  be  well  made  in  green  sand  by  coating  the  surfaces  of  the  moulds 
and  gates  with  silver,  lead,  or  plumbago.  From  “blow-holes,” 
which  are  another  characteristic  element  likely  to  exist  in  strong 
metals,  it  can  be  said  that  aluminium-bronze  is  free.  Should  any 
exist  it  is  the  fault  of  the  moulder  or  his  mould,  as  the  metal  itself 
runs  in  iron  moulds  as  sound  and  close  as  gold.  Sand  moulds  to 
procure  good  work  must  be  well  vented,  and,  if  of  “dry  sand,” 
thoroughly  open  sand  mixture  should  be  used  and  well  dried.  The 
sand  for  “  green-sand  ”  work  is  best  fine,  similar  to  what  will  work 
well  for  brass  castings.  For  “  dry-sand  work  ”  the  mixture  should 
be  as  open  as  possible,  and,  for  blacking  the  mould,  use  the  same 
mixtures  as  are  found  to  work  well  with  cast-iron. 

To  Cast  Lead-pipe  Free  frotn  Flaws. — G.  Dolleschal,  of  Aix-la- 
Chapelle,  uses  the  following  contrivance :  A  round  vessel  for  the 
reception  of  the  melted  lead  terminates  in  the  centre  below  in  a  short 
open  tube  with  an  interior  diameter  equal  to  the  exterior  of  the 
lead-pipe  to  be  cast.  Through  this  tube  and  through  the  entire  vessel, 
exactly  in  the  centre,  runs  a  long  core-tube  the  exterior  width  of 
which  is  equal  to  the  interior  of  the  lead  pipe.  By  a  driving  gear 
the  vessel  can  be  moved  in  an  exactly  straight  line  from  below  to 
above.  It  is  first  brought  upon  the  bottom  plate  of  the  entire 
arrangement  so  that  the  short  tube  is  closed  below.  The  melted 


214 


THE  METAL  WORKER’S  IIANDY-BOOK. 


lead  is  then  poured  in  and  the  vessel  moved  slowly  upwards  so  that 
the  lead  has  time  to  congeal  in  the  annular  space  between  the  short 
tube  and  the  core-tube,  whilst  it  remains  fluid  in  the  vessel.  The 
lead-pipe  thus  gradually  grows  from  below  to  above  until  the  lead 
in  the  vessel  is  exhausted  or  the  upper  end  of  the  core-tube  is  on  a 
level  with  the  upper  portion  of  the  vessel. 

Dense  and  Flexible  Copper  Castings  are  obtained  by  adding 
cryolite  and  sugar  of  lead  to  the  copper  after  it  is  melted.  The 
proportions  are  as  follows :  Pulverized  cryolite,  2  lbs.  ;  and  sugar 
of  lead,  8*4  ozs.  to  200  lbs.  of  copper;  a  further  addition  of  2 
lbs.  of  borax  being  also  advisable.  The  quantities  of  the  additions 
may  be  varied  according  to  circumstances.  The  mixture  of  cryo¬ 
lite  and  sugar  of  lead,  with  or  without  borax,  is  added  after  the 
copper  is  melted.  When  the  compound  is  entirely  melted,  which 
will  be  the  case  in  10  to  15  minutes,  the  melted  copper  is  poured 
into  the  mould. 

Wronghl-iron  (or  Mitis)  Castings. — When  wrought-iron  is  heated 
to  a  high  temperature  it  does  not  pass  quickly  into  the  fluid  state, 
but  for  a  large  increase  of  temperature  above  the  point  at  which  it 
first  softens  it  will  remain  thick  or  mushy.  At  a  very  high  temper¬ 
ature  it  can  be  made  sufficiently  fluid  to  pour  into  moulds,  but  the 
castings  thus  made  are  notably  unsound  and  weak.  It  was  dis¬ 
covered  by  Mr.  Wittenstroem,  of  Stockholm,  working  with  the  co¬ 
operation  of  Mr.  L.  Nobel,  of  St.  Petersburg,  that  if  a  small 
amount  of  aluminium  is  added  to  a  charge  of  wrought-iron  which 
has  been  heated  until  pasty,  the  iron  immediately  liquefies  and  can 
be  poured  into  castings  having  all  the  properties  of  wrought-iron 
except  fibre,  and  as  sound  as  if  of  cast-iron.  These  castings  were 
called  “Mitis”  castings  because  of  their  softness  in  contrast  with 
cast-iron  castings. 

The  details  of  the  production  of  Mitis  castings  are  as  follows: 
As  the  raw  material  to  operate  on,  wrought-iron,  scrap  or  mild 
steel  are  equally  suitable.  It  was  found  that  some  of  the  best  re¬ 
sults  are  to  be  obtained  by  using  Swedish  scrap  iron  or  English 
hematite  iron,  that  is,  materials  containing  less  than  o.  1  per  cent, 
of  phosphorus,  which  is  a  very  injurious  ingredient  if  present  in 


CASTING  AND  FOUNDING. 


215 


much  larger  quantity.  Using  a  mixture  with  poorer  quality  of 
iron,  with  phosphorus  running  up  to  0.15  per  cent.,  good  results 
may  still  be  obtained — that  is,  the  castings  still  compare  favorably 
with  ordinary  malleable  castings.  In  using  scrap  steel,  which  is 
necessarily  low  in  phosphorus,  it  was  found  that  manganese  inter¬ 
fered  with  the  production  of  good  castings,  a  result  rather  unex¬ 
pected.  Since  almost  every  melter  devises  various  mixtures  of  his 
own,  as  circumstances  permit,  it  is  but  natural  that  the  best  features 
of  the  Mitis  process  are  found  united  with  some  other  old-estab¬ 
lished  practices.  Thus  in  one  Mitis  plant  in  the  United  States  the 
mixture  for  melting  was  composed  of:  Mitis  scrap,  35  per  cent.; 
hematite  muck  bar,  35;  wrought-iron  punch ings,  12^;  soft  steel 
scrap  (o.  1  per  cent,  carbon),  12^;  white  pig-iron,  3;  ferro-silicon 
(10  per  cent,  silicon),  1 ;  ferro-aluminium  (6  per  cent,  alumi¬ 
nium),  Yz.  It  seems  that  in  this  charge  the  melter  used  a  little 
white  iron  as  a  flux,  which  would  probably  introduce  0.1  per  cent, 
of  carbon ;  then  the  virtues  of  ferro-silicon  for  making  sounder 
castings  are  utilized  by  adding  0.1  per  cent,  of  silicon  to  the 
charge;  lastly,  0.04  per  cent,  of  aluminium  was  introduced. 

In  general  it  may  be  said  that  if  iron  free  from  impurities  is 
used,  very  good  castings  are  obtained ;  if  iron  is  used  with  a  large 
percentage  of  phosphorus,  proportionally  brittle  and  unsatisfactory 
castings  result. 

The  ferro-aluminium  used  should  be,  for  similar  reasons,  free 
from  any  considerable  amount  of  such  impurities  as  generally 
injure  wrought-iron. 

Since  the  castings  are  almost  identical  in  composition  with  the 
charge  of  iron  melted,  the  following  analyses  of  Mitis  metal,  made 
by  Mr.  Edward  Riley,  will  show  the  range  of  material  or  mixture 
to  which  the  process  has  been  successfully  applied  : 


Raw  material. 

Carbon. 

Silicon. 

Phosphorus. 

Manganese. 

Hematite  bar . 

0.067 

0.161 

0.068 

0.022 

Swedish  scrap . 

0.053 

0.044 

0.077 

0.027 

Refined  iron . 

0,130 

0.124 

0.137 

O.OI4 

THE  METAL  WORKER’S  HANDY-BOOK. 


21  fi 


Table  Continued. 


Raw  material. 

Carbon. 

Silicon. 

Phosphorus. 

Manganese. 

]/2  Staffordshire  iron ' 
]/2  Swedish  scrap 

0.130 

0-035 

0.150 

0.026 

Staftordshire  iron 
y  Hematite  bar 

0.070 

0.093 

0.194 

0.014 

Slaflordshire  iron .... 

0.106 

0.080 

0.250 

O.014 

The  above  figures  are  percentages;  sulphur  was  present  in  all  as 
a  trace.  The  first  in  the  table,  those  low  in  phosphorus,  gave  the 
best  castings,  the  last  the  poorest ;  with  over  %  per  cent,  of  phos¬ 
phorus  the  castings  were  brittle. 

The  charge  of  wrought-iron  is  placed  in  covered  crucibles  and 
brought  to  a  temperature  of  about  2200°  C.,  at  which  heat  it 
just  loses  the  solid  and  assumes  the  pasty  condition.  If  it  were 
desired  to  cast  the  iron  without  adding  aluminium  it  would  be 
necessary  to  superheat  it  several  hundred  degrees  above  this  point, 
not  only  to  give  it  the  desired  fluidity  but  also  to  permit  it  being 
carried  about  the  casting  shop.  It  is  during  this  superheating  that 
a  large  part  of  the  gases  contained  in  the  molten  iron  are  absorbed. 
If,  therefore,  the  charge  is  treated  with  aluminium  immediately 
on  reaching  the  melting  point,  the  effect  is  such  that  this  super¬ 
heating  with  its  accompanying  deterioration  of  the  iron  is  rendered 
unnecessary.  This  is  possible  for  the  reason  that  on  adding  ferro- 
aluminium  sufficient  to  introduce  0.05  to  0.1  per  cent,  of  alu¬ 
minium  the  charge  immediately  liquefies,  and  is  so  far  from  its 
setting  point  that  it  can  be  removed  from  the  furnace  and  poured 
into  numerous  moulds,  retaining  all  the  time  its  exceptional  fluidity. 
The  metal  acts  just  as  if  it  had  been  superheated  several  hundred 
degrees,  but  this  has  been  accomplished  without  leaving  it  in  the 
furnace  for  half  an  hour  or  so,  thus  attaining  an  economy  in  fuel 
which  is  not  to  be  ignored.  When  the  crucible  is  taken  from  the 
furnace  the  charge  is  perfectly  dead  melted,  lies  quiet  in  the  crucible, 
evolves  no  gas,  and  teems  like  molten  silver.  It  is  cast  in  either 


CASTING  AND  FOUNDING. 


217 


sand  or  iron  moulds,  and  on  account  of  its  fluidity  does  not  require 
large  heads  to  bring  the  castings  up  sharp  and  show  the  finest  impres¬ 
sions  of  the  mould.  The  material  being  primarily  wrought-iron, 
the  castings  do  not  have  to  be  annealed  before  using.  The  thinnest 
or  most  complicated  castings,  which  it  would  be  almost  impossible 
to  forge  in  wrought-iron,  can  be  produced,  thus  furnishing  dif¬ 
ficult  forged  pieces  at  not  much  greater  expense  than  ordinary  cast¬ 
ings.  Mitis  castings  are,  in  short,  objects  cast  of  molten  iron  yet 
having  all  the  desirable  properties  of  wrought-iron. 

Casting  Stereoplates  by  the  Paper  Process. — Lay  a  sheet  of  tissue 
paper  upon  a  perfectly  flat  surface,  and  paste  a  piece  of  soft  printing 
paper  on  to  the  tissue  paper,  pressing  them  very  flat  and  even.  Oil 
the  form  of  type,  lay  the  paper  on  it,  and  cover  with  a  damp  rag ; 
beat  the  paper  evenly  into  the  type  with  a  stiff  brush,  then  paste  on 
it  a  piece  of  blotting  paper  and  repeat  the  beating-in  process,  after 
which  several  other  layers  of  soft,  tenacious  paper  must  be  pasted  on 
and  beaten  in  in  the  same  manner;  back  up  the  paper  with  a  piece 
of  cartridge  paper.  The  whole  must  then  be  dried  at  a  moderate 
heat  under  a  slight  pressure.  When  quite  dry,  brush  over  the  face 
of  the  paper  mould  with  plumbago  or  French  chalk.  When  this  is 
done  it  is  ready  for  the  matrix.  This  is  a  box  of  the  size  required 
for  the  work,  the  interior  of  which  is  type-high.  This  is  called  the 
gauge,  and  lifts  out  to  insert  the  paper  mould,  and  is  regulated  by 
hand  to  the  size  of  the  plate  required.  This  being  placed  inside, 
the  lid  is  shut  down  and  screwed  tight,  with  the  end  or  mouthpiece 
left  open.  The  metal  is  poured  in  at  the  orifice,  and  as  it  is 
mounted  to  swing,  the  box  is  moved  about  so  as  to  throw  the  metal 
well  down  and  make  a  solid  cast.  Then  water  is  dashed  on  the  box, 
the  screw-bar  unshackled,  the  lid  lifted,  the  plate  taken  off,  and  the 
paper  mould  is  ready  for  use  for  another  casting. 

Another  Stereotype  Process. — The  stereotyper  first  dries  the  form 
of  types  upon  an  iron  steam-table.  The  form  is  then  partially 
unlocked,  and  a  hand-brush  is  rubbed  over  the  surface  of  the  types, 
cleansing  them  preparatory  to  placing  over  the  entire  form  a  sheet 
or  sheets  of  thin  bank-note  paper  of  the  finest  quality,  previously 
wetted  to  insure  the  required  pliability.  This  paper  being  laid 


218 


TIIE  METAL  WORKER’S  IT  ANDY-BOOK. 


evenly  over  the  types,  the  workman  takes  a  long-handled  brush, 
made  of  short,  stiff  bristles,  with  which  he  beats  the  wet  paper 
evenly,  forcing  it  into  all  depressions  of  the  types,  taking  care  not 
to  break  the  paper.  The  work  being  finished,  a  dampened  sheet 
of  thicker,  more  ordinary  paper  is  placed  over  the  first.  This  is 
also  brush-hammered  down  upon  the  types,  and  followed  by  another 
sheet  of  paper  thinly  coated  with  a  preparation  of  whiting  and 
starch.  Again  the  brush  is  used  to  beat  this  home,  after  which  a 
brown-paper  backing  is  put  on,  and  then  the  form  of  types,  covered 
by  the  before-mentioned  sheets  of  paper,  is  trundled  to  another 
steam-table,  where  it  is  slid  under  a  powerful  screw-press,  several 
blankets  folded  over  it,  and  all  firmly  held  down  until  the  paper 
matrix  is  dry-hardened,  or  “cooked,”  as  the  workmen  express  it. 
The  papering  process  occupies  three  or  four  minutes,  the  cooking 
about  twice  as  long.  The  matrix  is  now  peeled  off  from  the  form, 
and  prepared  for  casting  by  sifting  it  over  with  finely  powdered  bo¬ 
rax,  which,  with  a  soft  brush,  is  thoroughly  rubbed  into  the  sunken 
surface  left  by  the  types.  The  surplus  borax  having  been  removed, 
the  matrix,  which  now  resembles  hard  but  pliable  pasteboard,  is 
ready  for  the  casting  box,  which  is  made  of  iron,  either  straight  or 
curved,  to  suit  the  press-bed.  Handle-irons  hold  the  matrix  in  its 
proper  place,  at  the  exact  distance,  about  half  an  inch,  necessary 
for  the  thickness  of  the  stereotype  plate,  which  is  made  by  pouring 
a  quantity  of  hot  type-metal  into  an  open  end  of  the  casting  box. 
This  metal,  dropping  between  one  surface  of  the  casting  box  and 
the  sunken  surface  of  the  matrix,  fills  up  the  latter  without  burning 
it.  A  few  moments  are  allowed  for  cooling,  and  then  the  matrix  is 
stripped  from  the  warm  plate,  which  is  subsequently  prepared  for 
the  press  by  trimming  down  all  thick  lines,  or  chiselling  away  any 
superfluous  metal,  paring  off  the  edges,  filing,  and  otherwise  treating 
the  stereotype  after  the  usual  manner.  Circular  saws  driven  by 
steam  and  hand-cutting  machinery  of  various  kinds  are  used  in 
finishing,  the  whole  operation  of  stereotyping  occupying  from  15 
to  20  minutes.  A  second  plate  may  be  obtained  from  the  original 
matrix  in  about  2  minutes,  and  almost  any  number  of  castings  can 
be  taken  by  careful  workmen. 


CASTING  AND  FOUNDING. 


219 


Manufacture  of  Chilled  Wheels. — The  following  is  a  brief  descrip¬ 
tion  of  the  largest  establishment  for  the  manufacture  of  chilled 
wheels  in  the  United  States,  and  the  manner  in  which  the  work  is 
advanced  from  stage  to  stage :  The  foundry,  which  is  of  course  the 
most  important  portion  of  the  whole  works,  is  a  fine  building,  with 
two  lines  of  rails  running  down  its  whole  length,  except  opposite  ' 
the  furnaces.  The  rails  are  laid  to  a  gauge  of  about  io  feet,  and 
upon  them  are  placed  12  light  travelling  cranes,  with  a  platform 
attached  to  the  centre-post,  and  upon  which  the  man  working  the 
crane  stands  and  controls  its  movements,  both  in  hauling  the  moulds 
and  ladles,  and  in  moving  the  crane  from  place  to  place  upon  the 
line,  the  crane  being  geared  for  travelling.  The  floor  of  the  foundry 
is  so  laid  out  that  there  is  room  on  either  side  of  both  pairs  of  rails 
for  a  row  of  moulds,  and  in  the  centre  of  the  building  is  a  path 
about  4  feet  wide.  Against  one  side  of  the  building,  and  in  the 
centre  of  its  length,  are  five  cupolas,  three  of  4  feet  6  inches  internal 
diameter,  and  two  smaller  ones  of  18  inches  in  diameter.  The 
former  are  employed  in  melting  the  iron  for  the  wheels,  the  latter 
chiefly  for  experimental  purposes.  The  three  cupolas  are  tapped 
into  converging  channels,  all  running  into  one  large  tipping  reser¬ 
voir,  from  which  the  small  ladles  are  supplied.  The  blast  to  the 
cupolas  is  furnished  by  a  vertical  blowing  engine,  with  two  blowing 
cylinders,  one  at  the  top  of  the  machine  and  one  at  the  bottom, 
with  the  steam-cylinder  between  the  two. 

The  mixing  of  the  irons  for  the  cupola  is  the  most  important  and 
difficult  operation  in  the  whole  course  of  manufacture.  Besides  the 
steel-scrap  nothing  but  charcoal  pig-iron  is  employed,  and  of  this 
from  twelve  to  twenty  different  kinds,  all  of  the  highest  class,  are 
used  in  varying  proportions.  But  these  mixtures  have  to  be  altered 
frequently,  owing  to  irregularities  in  the  nature  of  the  metal,  and 
daily  tests  are  made,  with  a  view  of  ascertaining  what  changes,  if 
any,  have  to  be  introduced  into  the  next  day’s  work.  The  propor¬ 
tions  of  the  mixture  being  decided  upon,  the  cupolas  are  charged, 
a  ton  of  coal  being  first  put  into  the  bed  of  each  furnace.  The  charge 
is  then  carefully  loaded  upon  trucks  upon  a  weighing  platform. 
Piles  of  the  various  pigs  are  placed  in  their  proper  order  around  the 


220 


THE  METAL  WORKER’S  HANDY-BOOK. 


truck,  and  there  is  a  drum  upon  the  weighing  machine,  on  which  a 
sheet  of  paper  is  placed,  and  the  weight  of  each  different  pig,  in 
proper  order,  is  written  upon  it.  For  instance,  the  workman 
commences  with  250  lbs.  of  coal  in  his  truck;  he  then  places  125 
lbs.  of  old  steel  rails,  125  lbs.  of  cinder  pig,  350  lbs.  of  old  wheels, 
and  so  on  through  the  long  list  of  charcoal  pig-iron  employed,  the 
old  material  being  placed  at  the  bottom  of  the  furnace.  The 
weighing  platform  is  so  arranged  as  to  record  the  accumulating 
weights  as  the  drum  revolves,  bringing  before  the  workman  the 
name  and  quantity  of  each  successive  ingredient,  which  he  takes 
from  its  respective  heap  before  him.  As  soon  as  it  is  loaded,  the 
truck  is  raised  to  the  top  of  the  cupola  by  an  hydraulic  lift.  The 
moulds,  when  ready,  are  placed  down  the  building  in  four  rows,  one 
on  each  side  of  the  two  lines  of  rail  upon  which  the  cranes  run. 
The  patterns  used  are  almost  all  in  iron,  and  the  chills  in  the 
moulds  are  of  cast-iron.  One  workman  can,  on  an  average,  mould 
ten  wheels  a  day,  but  all  failures  in  the  casting,  arising  from  any 
carelessness  in  moulding,  are  charged  to  him  on  a  rapidly  increasing 
scale. 

Before  the  metal  in  the  cupola  is  ready  to  run,  a  charcoal  fire  is 
lighted  in  the  receiver  before  spoken  off,  in  order  to  warm  it,  and 
also  that  when  filled  the  metal  may  be  covered  with  charcoal  and 
oxidation  checked.  In  a  similar  manner  the  ladles,  of  which  there 
are  a  very  large  number  employed,  have  burning  charcoal  placed  in 
them,  and  they  are  internally  coated  in  the  usual  way.  These  ladles 
are  cylindrical  pots  made  of  sheet-iron  and  mounted  each  on  a 
pair  of  wheels  for  facility  of  transport.  On  the  sides  of  each 
ladle  are  two  sockets,  into  one  of  which  is  placed  the  end  of  a 
handle  with  forked  ends.  The  ladle  being  run  up  to  the  receiver, 
the  latter  is  tipped  over  by  the  gearing  attached  to  it,  and  the  ladle 
is  charged  ;  it  is  then  brought  along  the  floor  to  the  crane,  which 
takes  hold  of  it  ;  the  two  square-ended  handles  before  mentioned 
are  inserted  in  the  holes  in  the  axles,  the  ladle  is  raised,  and  the 
iron  poured  into  the  mould.  The  chilled  portion  of  the  wheel 
sets  almost  as  soon  as  it  comes  into  contact  with  the  chills,  and  in 
a  very  short  time  after  the  casting  has  been  made,  the  flasks  are 


CASTING  AND  FOUNDING. 


221 


removed,  the  sand  knocked  away,  and  the  red-hot  wheel  is  placed 
on  a  truck  to  be  taken  to  the  annealing  pits.  This  process  is  one 
of  the  most  important  of  the  series.  If  the  wheel  be  allowed  to 
cool  in  the  open  air  severe  internal  strains  are  created  which  will 
sometimes  be  sufficient  to  destroy  the  casting,  and  open  air  cooling 
was  the  chief  cause  of  failure  in  the  early  periods  of  this  class  of 
wheel-making. 

The  annealing  ovens  are  placed  at  one  end  of  the  foundry,  and 
below  the  floors,  the  top  of  the  ovens  being  at  that  level.  Besides 
these  ovens  of  very  large  diameters  for  extra-sized  wheels,  chilled 
tyres,  etc.,  there  are  48  pits  ranged  in  6  rows  of  8  each.  These 
rows  are  divided  into  pairs,  each  pair  of  16  pits  being  devoted  to 
the  reception  of  one  day’s  production,  the  period  required  for 
annealing  being  3  days.  By  this  arrangement,  when  the  last  two 
rows  of  ovens  are  charged,  the  first  two  rows  can  be  emptied  and 
refilled,  so  that  the  work  proceeds  without  interruption  and  in 
regular  rotation.  Two  hydraulic  cranes,  with  the  booms  revolving 
upon  a  fixed  post,  are  placed  upon  the  floor  and  command  the 
whole  area  occupied  by  the  ovens.  The  boom  of  each  crane  is 
made  double,  and  upon  it  runs  to  and  fro  a  small  carriage,  from 
which  hangs  the  chain,  carrying  at  the  lower  end  the  hooks  by 
which  the  wheels  are  handled.  This  attachment  consists  of  three 
arms  with  flattened  ends  turned  over  so  as  to  grip  the  wheel.  The 
upper  ends  of  these  arms  are  hinged  together,  and  as  they  tend 
always  to  fall  inward,  they  hold  the  wheel  tightly,  but  by  moving  a 
single  attachment  the  arms  are  thrown  outward  when  it  is  desired 
to  release  the  wheel.  The  motion  of  the  cranes  is  controlled  by 
one  man,  fixed  stops  being  provided  on  the  guiding  apparatus,  so 
that  when  the  crane  is  adjusted  for  filling  one  oven  it  remains  in 
that  position  till  it  is  thrown  over  to  the  next. 

The  ovens  or  annealing  pits  are  cylinders  of  sheet-iron  inch 
thick,  about  66  inches  in  diameter,  and  of  sufficient  depth  to  con¬ 
tain  easily  18  wheels  writh  cast-iron  distance-pieces  between  them. 
They  are  lined  with  brickwork,  and  being  of  considerable  depth, 
they  descend  into  a  lower  floor.  The  lower  parts  are  enclosed  in 
a  large  rectangular  chamber,  one  for  each  set  of  ovens.  Within 


222 


THE  METAL  WORKER’S  HANDY-BOOK. 


this  chamber,  and  for  a  short  distance  above  it,  fire-brick  is  used 
instead  of  ordinary  brickwork  as  in  the  upper  portions,  and  within 
the  cylinder  a  circular  foundation  of  brickwork  is  set,  upon  which 
are  placed  the  wheels  on  being  lowered  by  the  crane.  The  whole 
of  this  weight  then  is  transferred  direct  to  the  foundation  of  the 
building.  At  the  end  of  each  of  the  three  rectangular  chambers 
already  mentioned  is  a  furnace,  and  each  chamber  is  divided  down 
the  whole  of  its  length  by  a  perforated  flue;  through  these  perfora¬ 
tions  the  heat  from  the  furnace  passes  and  enters  the  lower  ends  of 
the  ovens.  These  furnaces  are  required  to  prevent  the  too  sudden 
cooling  of  the  castings,  but  only  %  ton  of  coal  is  burned  for  each 
full  day’s  production.  Flues  leading  to  the  chimney  carry  off  the 
heated  gases  from  the  upper  parts  of  the  ovens,  and  so  the  process 
of  cooling  is  thus  very  gradually  carried  on,  until  at  the  end  of 
three  days  the  wheels  are  ready  for  removal.  The  three  large  an¬ 
nealing  pits  mentioned  above  are  somewhat  differently  arranged. 
To  save  room  they  are  not  carried  down  so  low  as  the  other  ovens, 
but  terminate  at  a  height  of  about  7  feet  above  the  floor,  each 
being  supported  upon  a  central  column.  When  they  are  used  a 
fire  is  lighted  in  the  bottom  of  each  pit,  the  wheels  are  put  in 
and  covered  over,  and  the  oven  is  allowed  gradually  to  cool. 

On  being  removed  from  the  pit  the  wheels  are  taken  into  the 
cleaning  and  testing  room.  Here  the  sand  is  removed,  and  the 
wheels  tested  by  hammering  under  a  sledge  as  well  as  by  a  small 
hammer,  while  the  thread  is  cut  at  intervals  by  a  chisel.  The 
heavy  blows  to  which  the  wheel  is  subjected  never  fail  in  detecting 
faults  when  such  exist,  and  when  they  are  discovered  the  wheel  is 
removed  to  be  broken  up.  About  10  per  cent,  of  the  whole  pro¬ 
duction  is  rejected,  but  occasionally  this  proportion  is  very  much 
higher. 

In  order  to  keep  the  quality  of  the  wheels  up  to  the  desired  stand¬ 
ard,  a  large  number  of  test  pieces  are  cast  every  day  and  submitted 
to  examination.  By  this  means  an  accurate  knowledge  of  the 
nature  of  the  wheels,  the  character  of  the  chill  and  other  points 
is  obtained;  the  data  are  carefully  recorded,  and  if  the  tests  are 
satisfactory  the  wheels  corresponding  to  the  test  piece  are  delivered 


CASTING  AND  FOUNDING. 


223 


into  stock.  If  not  they  are  returned  to  be  broken  up.  The  sound 
wheels  are  finally  taken  to  the  machine-shop  where  they  are  bored, 
and,  if  desired,  fitted  with  their  axles.  The  tools,  therefore,  in  this 
shop  are  few  in  number,  consisting  of  three  boring  machines,  a 
press  for  forcing  the  wheels  on  or  for  drawing  them  off  the  axles, 
and  a  number  of  lathes. 

The  average  life  of  a  chilled  cast-iron  wheel  of  first  quality  is 
asserted  to  be  50,000  miles  for  passenger  and  100,000  miles  for 
freight  traffic. 

Casting  of  Zinc. — Great  difficulties  were  at  first  met  with  in  the 
application  of  zinc  to  casting.  Since  these  have  been  conquered 
quite  a  branch  of  industry  has  been  developed,  which  furnishes 
many  articles  for  household  and  other  uses.  The  extreme  brittle¬ 
ness  of  zinc  is  no  longer  a  hindrance,  since  it  has  been  ascertained 
that  it  can  be  overcome  by  heating  the  metal  to  a  certain  degree 
(302°  to  31 70  F.).  Zinc  fills  the  moulds  very  sharply,  and  is, 
therefore,  especially  adapted  to  ornamental  and  art  castings.  For 
larger  castings  in  one  piece  it  is  not  suitable,  as  it  readily  tears  on 
account  of  strong  shrinkage,  but  the  patterns  may  be  divided  and 
the  castings  united  by  soldering.  From  such  castings  colossal  stat¬ 
ues  can  be  made,  which  when  coppered  by  the  galvanic  process 
resemble  the  best  bronze  castings.  For  household  use  zinc  is 
worked  into  ink-stands,  lamps,  candlesticks,  signs,  etc. 

The  zinc  is  generally  melted  in  cast-iron  kettles  and  poured  out 
with  ladles.  Green  sand  serves  as  moulding  material,  though  loam 
may  also  be  used.  The  sand  must  be  genuine  moulding  sand, 
fine  and  not  too  loamy ;  the  moulds  are  not  heated.  The 
temperature  of  melting  should  not  be  too  high,  as  otherwise  the 
metal  readily  oxidizes.  Oxidizing  may  be  prevented  by  covering 
the  metal,  while  in  crucible  or  ladle,  with  a  layer  of  common  salt 
or  a  little  hydrochloric  acid,  which  amounts  to  the  same,  a  coat  of 
zinc  oxide  being  instantly  formed  on  the  surface  of  the  melted 
metal,  which  effectually  prevents  further  oxidation  from  the  action 
of  the  oxygen  in  the  atmosphere.  It  is  an  improvement  to  keep  a 
layer  of  charcoal  on  top  of  the  zinc,  or  a  soft  metal  which  can  be 
melted  in  a  ladle  ]  the  casting  of  oxide  forms  a  protection  against 


224 


THE  METAL  WORKER’S  HANDY-BOOK. 


oxidation  to  a  certain  degree  only,  while  the  layer  of  charcoal 
tends  to  reduce  the  oxide  again  to  its  metallic  form.  Indeed,  it  is 
possible  to  recover  lead,  tin,  zinc  and  antimony  from  the  “dross” 
or  oxide  which  gathers  in  the  ladle,  it  being  only  necessary  to  melt 
the  oxide  with  charcoal,  salt  and  soda,  to  get  it  again  into  useful 
shape.  The  dross  should  be  powdered,  likewise  the  salt,  charcoal 
and  soda.  Mix  them  together  and  melt.  The  soda  and  salt  melt 
into  a  pasty  mass,  and  the  carbon  unites  with  the  oxygen  of  the 
dross,  leaving  the  metal  free,  all  but  burning  off  the  charcoal. 
The  salt  and  soda  act  simply  as  a  flux  in  reducing  the  oxides. 

For  hollow  castings  the  cores  are  made  of  sand,  but  to  prevent 
the  danger  of  tearing  on  account  of  the  considerable  shrinkage  of 
the  metal,  the  scaffolding  around  which  the  core  mass  is  moulded 
must  be  so  arranged  that  it  can  be  readily  withdrawn. 

Metallic  moulds,  if  used,  must  be  previously  heated.  For 
moulding  the  ordinary  flasks  used  in  brass  and  iron  foundries  are 
employed.  To  obtain  from  patterns  of  larger  pieces,  castings  of 
slight  thickness,  the  entire  pattern  is  first  moulded  in  the  lower 
part  of  the  box  ;  the  top  part  of  the  box  is  then  placed  in  position, 
the  depressed  mould  is  scattered  over  with  coal-dust  and  the  sand 
in  the  upper  part  of  the  box  carefully  pressed  into  the  depression 
of  the  mould.  The  upper  part  of  the  box  is  then  again  removed 
and  sufficient  of  the  moulded  sand  mass  for  the  intended  thickness 
of  the  metal  scraped  off. 

Apparatus  for  Casting  Metal,  patented  by  H.  A.  Brustlein,  of 
Firming,  France.  The  casting  ladle  g  (Fig.  6)  sits  upon  a  crane 
and  can  be  moved  in  a  circle  as  well  as  up  and  down  ;  moreover, 
it  can  be  horizontally  shifted  to  and  fro.  On  the  discharge  aperture 
in  the  bottom  is  a  pipe  a,  which  terminates  below  in  an  enlarged 
mouth-piece  b  of  burnt  clay.  This  serves  the  purpose  of  changing 
the  course  of  the  metal  flowing  out,  and  is  so  arranged  that  the 
metal  cannot  fall  vertically  upon  the  bottom  of  the  mould,  but 
must  flow  over  the  slightly  rising  bottom  in  the  mouth-piece  b. 
The  bottom  of  the  casting  mould  h  consists  of  a  comparatively 
thin  metal  plate  c,  which  rests  upon  the  frame  d,  supported  by  the 
plate  f.  The  latter  in  the  centre  passes  into  a  water-pipe  which 


CASTING  AND  FOUNDING. 


225 


feeds  the  rose  e,  whereby  the  bottom  c  is  cooled.  To  the  plate  /is 
secured  a  bevel  wheel  i,  by  means  of  which  the  entire  mould  is 
revolved,  whilst  the  rose  e  remains  stationary. 

Preparation  of  Chills  for  Casting  Metal. — To  obtain  a  dense 
casting  in  chills,  the  mould  previously  made  hand-warm  is  smeared 
over  with  old  lard  and  then  dusted  with  soap-stone  powder.  By 
this  means  an  expanding  layer  is  formed  during  casting  between  the 
chill  and  the  casting,  whereby  the  gases  still  present  in  the  interior 
of  the  metallic  mass  are  forced  to  escape  through  the  fluid  ingot. 


Fig.  6. 


Painting  and  Varnishing  Patterns. — As  a  precaution  against 
defects  in  the  wood,  and  also  as  a  preservative  for  the  patterns, 
they  are  usually  coated  with  varnish  or  oil  paint.  Thus  their 
capillary  attraction  is  lessened  and  their  surfaces  made  smooth  and 
glossy.  There  is  nothing  better  for  these  purposes  than  a  moderately 
hard-drying  oil  paint,  black-leaded  over  when  dry.  One  mode  of 
coating  patterns  is  to  paint  them  with  a  thin  coat  of  oil  paint,  con¬ 
sisting  of  red-lead  and  acetate  or  sugar  of  lead.  Allow  this  to  dry 
in  a  warm  room,  then  carefully  rub  over  with  sand-paper  and  finish 
15 


226 


THE  METAL  WORKER’S  HANDY-BOOK. 


with  powdered  chalk,  or  a  thin  coat  of  less  rapidly  setting  oil  paint 
may  be  applied,  and  the  surface  finished  with  pumice-stone  and 
very  fine  glass-paper.  Rub  well  with  a  soft  cloth,  then  put  on  a 
coat  of  black-lead  mixed  with  beer,  applied  with  a  hard  brush. 

When  only  one  or  two  castings  are  required  from  a  pattern, 
especially  if  it  should  be  of  an  ornamental  and  delicate  character, 
tli is  coating  of  black-lead  and  beer  may  be  applied  directly  to  the 
naked  wood  of  the  pattern.  This  plan  answers  very  well  where 
the  wooden  pattern  is  to  be  employed  simply  for  the  production 
of  a  metallic  pattern.  But  it  is  certainly  desirable  that  patterns 
which  have  to  be  used  several  times  should  be  painted  in  oil,  more 
especially  when  they  contain  joints  made  in  glue. 

For  large,  coarse  work,  a  thin  coat  of  common  lead-color  oil 
paint,  with  slight  finish  of  black-lead  put  on  dry,  is  a  cheap  and 
simple  protection. 

For  wheel  patterns  the  following  paint  has  been  recommended 
as  giving  excellent  results  in  the  moulds  and  a  smooth  surface  on 
the  castings:  A  first  coat  is  applied  of  a  paint  made  of  thin  drying 
oil,  spirits  of  turpentine,  and  pure  white-lead  mixed  with  a  little 
crystallized  acetate  of  copper.  When  dry  this  is  smoothed  off  with 
pumice  stone,  then  a  second  very  thin  coat  of  the  same  paint  is 
applied,  with  the  addition  of  a  little  copal  varnish.  The  patterns 
are  then  slowly  dried,  special  attention  being  given  that  no  warping 
occurs.  The  paint  dries  very  hard,  but  after  a  while,  when  exposed  to 
wear  and  handling,  it  becomes  scratched,  when  it  ceases  to  give  such 
good  results  as  those  first  obtained.  This  defect  is  partially  reme¬ 
died  by  rubbing  the  surfaces  over  with  powdered  French  chalk. 

Some  patterns,  made  of  rather  hard  wood,  such  as  dry  mahogany, 
will  deliver  very  well  if  coated  with  copal  varnish. 

Weak  shellac  varnish  is  also  a  capital  protection  to  patterns ;  it 
is  easily  made  by  dissolving  to  2  parts  by  weight  of  shellac  in 
20  of  methylated  spirits.  The  ingredients  take  some  20  or  30  hours 
to  mix  in  cold  weather,  but  the  mixing  may  be  accelerated  by  the 
vessel  being  placed  on  a  stove  or  other  warm  place. 

B lack- leading  of  Patterns. — All  metallic  patterns  are  much  im¬ 
proved  in  their  “delivery”  by  being  finely  “black-leaded.” 


CASTING  AND  FOUNDING. 


227 


Prior  to  the  application  of  the  plumbago,  the  surface  of  brass  or 
gun-metal  patterns  should  be  roughened  by  leaving  them  wetted 
with  a  solution  of  sal-ammoniac.  Zinc,  solder,  or  type  metal,  or 
other  such  soft  alloys  will  take  the  black-lead  at  once,  if  the  surface 
be  free  from  grease  and  dirt. 

Varieties  of  Wood  Most  Suitable  for  Patterns. — The  following  is  a 
list  of  the  different  varieties  of  wood  most  suitable  for  pattern¬ 
making,  with  their  specific  gravities  : 


Cork 

Specific  gravity. 

American  pine  . 

•  0.37 

American  fir 

.  0.42 

Larch 

•  0.54 

Cowrie 

.  0.58 

Red  Honduras  cedar 

•  0.55 

Elm  .... 

•  0.55 

White  poplar 

.  0.34  to  0.53 

Willow 

.  0.42  to  0.5 

Sycamore  . 

.  0.60 

Lime  tree  . 

.  0.60 

Pear  tree  . 

.  0.66 

Cherry  tree 

.  0.71 

Maple 

•  0.75 

Apple  tree 

.  0.80 

Alder 

.  0.80 

Beech 

.  0.85 

Honduras  mahogany 

.  0.81  to  i. 06 

Boxwood  . 

.  1.03101.33 

To  Preserve  Iron  Patterns  from  Rusting,  and  to  make  them  deliver 
more  easily,  they  should  be  allowed  to  become  slightly  rusty  ;  next, 
they  should  be  warmed  sufficiently  to  melt  beeswax,  which  is  then 
rubbed  all  over  them,  and  nearly  removed ;  when  cold  they  are  to 
be  polished  with  a  hard  brush. 

To  Mend  Patterns. — For  mending  patterns  needing  temporary 
repairs,  or  for  making  additions  where  but  one  or  two  moulds  are 
to  be  made,  the  following  material  will  be  found  very  useful :  Melt 
together  i  lb.  beeswax,  i  lb.  resin,  and  i  lb.  paraffine  wax.  It  is 
well  to  note  that  the  beeswax  intended  is  the  wax  made  by  the 


228 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


bees,  and  not  the  wax  made  by  the  wholesale  dealers.  When  the 
genuine  article  is  used,  this  mixture  will  be  found  very  useful  for 
making  additions  to  patterns,  small  temporary  patterns,  and  for  a 
variety  of  purposes  in  the  pattern  shop. 

Glue  for  Pattern-makers. — Pattern-makers  mix  with  their  glue 
some  good  thin-drying  linseed  oil,  in  the  proportion  of  about  i  part 
of  oil  to  4  of  water.  The  oil  is  added  to  the  glue,  and  well  stirred 
in  whilst  hot.  This  glue  is  scarcely  affected  by  moisture,  and 
makes  a  strong,  sound  joint,  although  it  does  not  set  hard  and 
glossy  like  ordinary  glue. 

Improved  Method  of  Treating  Steel for  Casting. — This  method  con¬ 
sists  in  passing  melted  steel  or  iron  through  a  bath  or  filtering  medium 
of  a  purifying  and  deoxidizing  alloy  of  less  specific  gravity  than 
either  steel  or  iron,  such  bath  or  filtering  medium  rising  and  form¬ 
ing  a  stratum  or  film  on  the  surface  of  the  melted  steel  or  iron  while 
in  the  cupola  from  which  it  is  subsequently  tapped.  The  filtering 
medium  is  obtained  from  aluminous  iron  ore  containing  from  io  to 
12  per  cent,  of  titanium.  It  is  claimed  that  the  effect  of  passing 
the  steel  as  it  melts  through  this  deoxidizing  layer  is  to  clear  it  of 
impurities,  especially  those  of  a  gaseous  character,  and  the  resulting 
castings  are  free  from  honeycombs  and  blowholes.  The  steel  can 
be  reduced  to  the  mildest  temper  by  annealing. 


VIII. 

CEMENTS. 

Iron  Cements  or  Rust  Joints. — These  cements  contain  as  an 
essential  constituent  iron  filings  and  turnings  which,  as  well  as  the 
iron  surfaces  to  be  united  with  such  cement, ’are  quickly  oxidized 
by  the  addition  of  sal-ammoniac,  salts,  etc.,  whereby  the  cement 
increases  in  bulk,  and,  consequently,  a  complete  filling  up  of  the 
joints  is  effected.  They  serve  for  closing  joints  on  iron  pipes, 
vessels,  plates,  etc.,  for  cementing  iron  to  iron,  or  iron  to  stone. 


CEMENTS. 


229 


I.  Iron  Cement  which  Stands  Red  Heat. — Iron  filings,  4  parts; 
pulverized  fat  clay,  2 ;  and  finely  powdered  pieces  of  Hessian 
crucibles,  1.  The  ingredients  are  mixed  and  moistened  with  salt 
water.  Care  must  be  had  not  to  add  too  much  salt,  as  otherwise 
the  latter  would  fuse  and  run  from  the  joints.  In  using  this  cement 
for  joining  pipes  which  are  to  lay  in  the  fire,  it  is  put  between  the 
flanges  of  the  pipes,  and  pressed  together  by  screws.  It  can  be 
heated  only  when  dry  and  hard. 

II.  Cement  for  Uniting  Iron  Surfaces  and  Filling  in  Joi?its. — Mix 
100  parts  of  iron  filings,  free  from  rust  and  not  larger  than  rape 
seed,  part  of  coarsely  powdered  sal-ammoniac,  and  y2  part  of 
flowers  of  sulphur;  moisten  the  mixture  with  urine  and  beat  it,  with 
repeated  moistening,  until  it  becomes  heated,  dry,  and  brittle.  In 
this  state  it  is  placed  in  the  joints,  and  forced  in  as  tightly  as 
possible  with  chisel  and  hammer,  whereby  it  again  becomes  moist 
and  soft.  Finally,  the  joints  are  filled  up  evenly,  and  allowed  to 
dry  two  days,  when,  as  an  indication  of  good  cementing,  separate 
black  drops  must  appear  upon  the  hardened  crust.  The  cement 
does  not  adhere  to  tarred  kettles  or  dirty  and  greasy  joints.  To 
keep  it,  it  is  rammed  into  an  iron  pot  and  water  poured  over  it. 
For  use,  pour  off"  the  water,  add  to  the  mass  taken  out  sufficient  iron 
filings  to  give  it  the  necessary  consistency,  and  pour  the  water  back 
into  the  pot.  The  stronger  and  quicker  the  cement  rusts  in  the 
joints  the  better  it  acts.  The  proportions  used  vary,  however,  very 
much.  For  instance,  a.  Iron  filings,  30  parts;  sal-ammoniac,  x; 
sulphur,  x.  With  this  composition  the  danger  of  progressive  rusting 
is,  however,  greater  on  account  of  the  larger  quantity  of  sal- 
ammoniac  in  proportion  to  iron  filings  ;  or,  b .  Pulverized  cast-iron 
turnings,  50  parts;  sal-ammoniac,  2;  flowers  of  sulphur,  1;  or,  c. 
Pulverized  iron  filings,  100  parts,  and  pulverized  sal-ammoniac,  2 
parts.  The  mixtures  are  kept  in  well-closed  boxes  in  a  dry  place, 
for  use  moistened  with  urine,  and  applied  as  mentioned  under  II. 
The  cemented  places  must  be  heated  only  when  entirely  dry. 

III.  For  Blowing  Engines,  Blast  Pipes,  Hot-blast  Stoves,  etc. — 
Mix  iron  filings,  15  parts  ;  clay,  1  ;  and  common  salt,  1,  with  equal 
parts  of  vinegar  and  water,  or  with  urine,  to  a  cement. 


230 


TTTE  METAL  WORKER’S  ITANDY-BOOK. 


IV.  Chenot's  Iron  Cement. — Iron  reduced  from  iron  ores  by 
hydrogen-gas  is  kneaded  with  clay  or  gypsum.  An  addition  of 
urine,  ammonia,  or  vinegar  very  much  accelerates  the  hardening  of 
this  cement. 

V.  For  Gas  Retorts  and  for  Connecting  of  Parts  of  Iron  Exposed 
to  Heat. — Mix  thoroughly  26  lbs.  of  iron  filings,  iP/2  lbs.  of  cement, 
2  lbs.  of  gypsum,  7  ozs.  of  sal-ammoniac,  and  5^  ozs.  of  sulphur 
with  x  pint  of  vinegar,  and  stir  into  the  mixture  some  warm  water. 
If  the  cement  is  good,  small  brown  bubbles  are  formed  on  the  sur¬ 
face  in  drying.  Articles  joined  with  this  cement  must  be  protected 
from  continued  moisture,  as  otherwise  the  cement  swells  and  bursts 
the  articles. 

VI.  For  Smearing  Over  Joints  of  Iron  Water  Reservoirs. — Mix 
iron  filings  with  wine  vinegar  or  dilute  sulphuric  acid  (1  part  acid 
to  30  water),  and  press  the  mass  into  the  joints  ;  or,  mix  2  parts  of 
iron  filings  and  1  of  green  vitriol  to  a  paste  with  wine  vinegar. 

VII.  For  Cementing  Joints  or  Cracks  in  Iron  Stoves. — Mix  coarse 
iron  filings,  clay,  sand,  salt,  and  cow-hair  with  fresh  blood;  or, 
clay,  beech  wood-ash,  and  some  salt  with  water. 

VIII.  For  Air-tight  Oven  Doors. — Intimately  mix  120  parts  of 
iron  filings,  2  of  pulverized  sal-ammoniac,  8  of  powdered  feldspar, 
and  1  of  flowers  of  sulphur,  and  make  the  mixture  into  a  paste  with 
water.  This  cement  must  be  used  at  once. 

IX.  For  Fastening  Iron  Rods,  Cramps,  Hooks,  etc.,  Especially  in 
Stone. — Make  into  a  paste  3  parts  of  plaster  of  Paris  and  1  part  of 
iron  filings  with  water  or  glue  water.  According  to  another  direc¬ 
tion,  7  parts  of  plaster  of  Paris  to  1  of  iron  filings  are  used.  If, 
however,  the  articles  to  be  cemented  are  to  remain  white,  the  iron 
filings  are  omitted,  and  only  7  parts  of  plaster  of  Paris  and  3  of 
white  of  egg  with  a  sufficient  quantity  of  water  are  used. 

It  is  frequently  very  difficult  to  cement  articles  of  iron  together 
so  that  the  cemented  places  remain  tight,  even  in  the  fire,  to  prevent 
fluids  from  permeating.  If  one  of  the  above-described  cements  of 
iron  filings,  sulphur,  and  sal-ammoniac  is  used  for  the  purpose,  it 
becomes  almost  always  necessary  to  tighten  the  screws  in  a  short 
time  on  account  of  the  cement  slagging  together,  which  is  some- 


CEMENTS. 


231 


times  very  unhandy.  Under  certain  circumstances  the  cement  may 
also  be  attacked  by  the  fluid  in  the  apparatus,  which  of  course  would 
cause  leakage.  Furthermore,  the  articles  joined  together  easily 
warp  in  the  great  heat  or  expand  in  the  fire,  which  causes  the 
cement  to  give  way  or  to  crumble.  In  such  cases  packing  with  iron 
has  proved  very  effectual.  The  process  is  as  follows :  The  articles 
to  be  made  tight  are  first  made  bright  by  pickling  or  filing  ;  a  disk 
of  bright  wrought-iron  of  the  exact  shape  of  the  parts  to  be 
joined  and  moistened  with  vinegar  is  placed  between  them  and 
the  screw  or  rivet  tightened. 

Cement  for  Iron. — The  following  mixture  has  been  successfully 
used  for  the  cementing  of  iron  railing  tops,  iron  gratings  to 
stoves,  etc.,  in  fact,  with  such  effect  as  to  resist  the  blows  of  a 
sledge-hammer.  This  mixture  is  composed  of  equal  parts  of 
sulphur  and  white-lead  with  about  |  part  of  borax,  the  three  in¬ 
gredients  being  thoroughly  incorporated  together,  so  as  to  form  a 
homogeneous  mass.  When  this  composition  is  to  be  applied,  it  is 
wet  with  strong  sulphuric  acid  and  a  thin  layer  of  it  placed  between 
the  two  pieces  of  iron,  these  being  at  once  pressed  together.  In 
five  days  it  will  be  perfectly  dry,  all  traces  of  the  cement  having 
vanished,  and  the  work  having  every  appearance  of  welding. 

To  Cement  Iron  to  Iron. — Mix  powdered  cast-iron  bore  chips,  60 
parts;  sal-ammoniac,  2;  flowers  of  sulphur,  1;  and  stir  the  mix¬ 
ture  into  a  stiff  paste  by  adding  water.  The  cement  must  be  used 
while  fresh. 

Cement  for  Fastening  Iron  Articles  in  Stone. — Mix  good  plaster 
of  Paris,  7  parts ;  iron  filings,  1  ;  and  stir  the  mixture  into  a  paste 
with  water.  This  cement  dries  very  quickly. 

Cement  for  Repairing  Defective  Places  in  Castings. — One  part  of 
black  pitch  and  1  of  rosin  are  melted  in  a  crucible,  and  a  sufficient 
quantity  of  fine  iron  filings  added  to  form  a  stiff  mass,  which  is 
allowed  to  become  cool.  The  defective  place  is  heated,  a  piece  of 
the  cement  laid  upon  it  and  pressed  down  with  a  hot  iron. 

Cement  for  Iron  Stoves. — Mix  with  sufficient  water  to  form  a 
stiff  paste,  wood  ashes,  10  parts  ;  clay,  10  ;  burnt  lime,  4. 

Cement  for  Mending  Iron  Pots  and  Pans. — Take  2  parts  by 


232 


THE  METAL  WORKER’S  HANDY-BOOK. 


weight  of  sulphur  and  i  of  fine  black-lead.  Put  the  sulphur  in  an 
old  iron  pan,  holding  it  over  the  fire  until  it  begins  to  melt,  then 
add  the  black-lead  ;  stir  well  until  all  is  mixed  and  melted ;  then 
pour  out  on  an  iron  plate  or  smooth  stone.  When  cool  break  into 
small  pieces.  A  sufficient  quantity  of  this  compound  being  placed 
upon  the  crack  of  the  iron  pot  to  be  mended,  can  be  soldered  by 
a  hot  iron  in  the  same  way  a  tinsmith  solders  his  sheets.  If  there 
is  a  small  hole  in  the  pot  drive  a  copper  rivet  in  it  and  then  solder 
over  it  with  this  cement. 

Cement  for  Making  Joints. — I.  Mix  ground  lead  with  as  much 
finely  powdered  red-lead  as  will  make  it  the  consistency  of  soft 
putty. 

II.  Mix  equal  parts  of  white-lead  and  red-lead,  and  add  as  much 
boiled  linseed  oil  as  is  required  to  give  it  the  proper  consistency; 
or,  make  boiled  linseed  oil  and  red-lead  mixed  into  a  putty.  These 
cements  are  used  for  making  metallic  joints  sound.  The  following 
cements  are  cheaper : 

Grouvelle' s  Oil  Cement. — Mix  thoroughly  red-lead,  i  part ; 
white-lead,  2l/2  ;  perfectly  dry  clay,  2  (all  finely  pulverized),  with 
boiled  linseed  oil. 

Stephenson' s  Oil  Cement. — Litharge,  2  parts ;  lime  fallen  to  a 
powder,  1  ;  and  fine  sand,  1,  are  mixed  to  a  stiff  paste  with  hot 
linseed  oil.  The  cement  is  used  while  fresh  and  warm. 

Serb  at' s  Mastic. — Finely  pulverized  sulphate  of  lead  is  pounded 
together  with  1  part  of  old  linseed  oil  in  a  suitable  apparatus. 
Repeat  the  operation  twice,  adding  each  time  1  part  of  finely 
pulverized  pyrolusite.  It  is  then  preserved  in  a  stone  vessel  closed 
with  wet  bladder.  Another  direction  for  preparing  this  mastic  is 
as  follows  :  Triturate  5  parts  of  zinc  oxide  and  5  of  sulphate  of 
lead  with  about  4  of  linseed  oil,  then  add  gradually  10  parts  of 
finely  ground  pyrolusite  and  a  like  quantity  of  colcothar,  and  pound 
the  whole  in  a  cast-iron  mortar  with  an  iron  pestle,  adding  gradu¬ 
ally  100  parts  more  of  pyrolusite  and  a  like  quantity  of  colcothar. 
The  cement  is  good  when  sufficiently  thick,  and  at  the  same  time 
so  flexible  that  it  can  be  rolled  out  between  the  fingers  without 


CEMENTS. 


233 


breaking.  If  the  cement  has  become  hard  add  some  more  oil  and 
work  it  thoroughly  with  the  iron  pestle. 

Marteaux  and  Robert' s  Cement. — This  cement  may  be  used  for 
pipes,  steam-engine  cylinders,  etc.  It  is  prepared  from  pyrolusite, 
ioo  parts;  graphite,  12;  white-lead,  5;  red-lead,  3;  and  clay,  3. 
The  ingredients  are  pulverized,  sifted  and  mixed.  To  7  parts  of 
the  mixture  add  1  part  of  boiled  linseed  oil  and  make  the  whole 
into  a  paste,  which  is  heated  in  a  sheet-iron  pan  and  then  vigor¬ 
ously  pounded  so  that  it  becomes  soft,  after  which  the  alternate 
heating  and  pounding  is  twice  repeated. 

Diamond  Cement. — This  cement  is  recommended  for  steam- 
apparatus,  steam-boilers,  etc.,  since,  when  hard,  it  adheres  firmly 
to  the  metallic  surface  and  does  not  shrink.  According  to  Hager 
it  consists  of  linseed  oil  varnish,  16  parts;  litharge,  16;  whiting, 
15  ;  and  prepared  graphite,  50.  As  the  graphite  very  much  im¬ 
pedes  the  drying  in  of  the  linseed  oil  at  an  ordinary  temperature, 
the  mass  can  be  preserved  for  a  long  time  in  a  plastic  state. 

Glycerin  Cement  for  Iron. — According  to  Bant’noff  a  very  durable 
fire-proof  and  water-proof  cement  for  cementing  together  and 
tightening  even  very  large  iron  articles,  for  instance,  cracked 
boilers,  is  obtained  by  working  equal  parts  of  red-lead  and  litharge 
to  the  consistency  of  glazier’s  putty  with  concentrated  glycerin. 

Fire-proof  and  Water-proof  Cement. — To  4  or  5  parts  .of  clay 
thoroughly  dried  and  pulverized  add  2  parts  of  iron  filings  free 
from  oxide,  1  of  peroxide  of  manganese,  y2  of  sea  salt  and  y2 
of  borax.  Mix  these  ingredients  thoroughly  and  render  them  as 
fine  as  possible,  then  reduce  them  to  a  thick  paste  with  the  necessary 
quantity  of  water,  mixing  intimately.  It  must  be  used  imme¬ 
diately.  After  application  it  should  be  exposed  to  heat,  gradually 
increasing  almost  to  a  white  heat.  This  cement  is  very  hard,  and 
presents  complete  resistance  alike  to  a  red  heat  and  boiling  water. 
Another  method  is  as  follows  :  To  equal  parts  of  sifted  peroxide  of 
manganese  and  pulverized  zinc-white  add  a  sufficient  quantity  of 
commercial  soluble  glass  to  form  a  thin  paste.  This  mixture,  when 
used  immediately,  forms  a  cement  quite  equal  in  hardness  and  re¬ 
sistance  to  that  obtained  by  the  first  method. 


234 


THE  METAL  WORKER’S  HANDY-ROOK. 


Cement  for  Electrical  or  Chemical  Apparatus. — A  good  cement 
for  this  purpose  may  be  prepared  by  mixing  5  lbs.  of  resin,  1  lb. 
of  wax,  1  lb.  of  red  ochre  and  2  ozs.  of  plaster  of  Paris,  and 
melting  the  whole  at  a  moderate  heat. 

Acid-proof  Cement. — Make  a  concentrated  solution  of  silicate  of 
soda,  and  form  a  paste  with  powdered  glass.  This  simple  mixture 
will  sometimes  be  found  invaluable  in  operations  of  the  laboratory 
where  a  luting  is  required  to  resist  the  action  of  acid  fumes. 

To  Cement  Thin  Metal-sheets. — Dissolve  isinglass  cut  into  small 
pieces  in  little  water  at  a  moderate  heat  and  add  a  small  quantity 
of  nitric  acid,  the  proper  proportion  being  determined  by  experi¬ 
ment.  With  too  much  nitric  acid  the  cement  requires  weeks  for 
drying  and  with  too  little  it  does  not  adhere  well. 

To  Unite  Glass  and  Brass. — Melt  5  parts  of  resin  and  1  of  wax  . 
and  stir  into  the  melted  mass  1  part  of  burned  ochre  and  y  part 
of  plaster  of  Paris  ;  or,  melt  together  4  parts  of  pine  resin  and  1 
of  wax  and  stir  into  the  melted  mass  1  part  of  elutriated  brickdust 
or  chalk.  Apply  warm  to  the  heated  surfaces. 

To  Fasten  Metallic  Mountings  upon  Glass,  Porcelain,  etc. — Dis¬ 
solve  2  parts  of  glue  of  a  good  quality  in  water,  heat  the  solution 
over  a  coal-fire  and  add  1  part  of  good  linseed  oil  varnish  and  y2 
of  Venetian  turpentine.  The  cemented  articles  must  remain  tied 
together  for  40  to  60  hours. 

Cement  for  Fastening  the  Metal  Parts  upon  Glass  Lamps. — Resin, 
12  parts;  strong  lye,  16;  water,  20;  plaster  of  Paris,  20.  The 
resin  is  boiled  with  the  lye  until  it  is  entirely  dissolved  and,  when 
cold,  forms  a  tenacious  solid  mass.  This  is  sufficiently  diluted  by 
adding  the  water  and  the  plaster  of  Paris  is  then  carefully  worked 
in.  This  cement  is  insoluble  in  petroleum. 

To  Cement  Metal  Plates  on  to  Wooden  Boxes. — Melt  together  6 
parts  of  resin  and  y  of  linseed  oil  and  stir  into  the  melted  mass  1 
part  of  burnt  ochre  and  y2  part  of  plaster  of  Paris. 

To  Cement  Iron  to  Wood  or  Stone. — Melt  together  4  parts  of 
black  pitch  and  1  of  wax  and  stir  1  part  of  brickdust  into  the 
melted  mass. 

To  Fasten  Metals  on  Wood. — Prepare  a  thick  solution  of  glue 


CEMENTS. 


235 


and  stir  into  it  finely  ground  chalk  until  the  mass  has  acquired  the 
required  consistency.  For  fastening  metals,  especially  copper,  to 
sandstone  the  following  composition  may  be  used  :  Work  together 
7  parts  of  white-lead,  6  of  litharge,  6  of  bole,  4  of  powdered 
glass  and  4  of  linseed  oil  varnish  so  as  to  form  a  plastic  mass. 

Cement  for  Fastening  Metal  upon  Glass. — To  secure  metal  to  1 
glass  in  a  safe  and  quick  manner  the  use  of  the  following  cement  is 
recommended:  Intimately  mix  100  parts  by  weight  of  pulverized 
white  litharge  and  50  of  dry  white-lead  and  work  it  with  a  mixture 
of  3  parts  of  boiled  linseed  oil  and  1  of  copal  lacquer  to  a  plastic 
mass.  The  cementing  itself  is  very  simple.  The  lower  surface  of 
the  metal  is  coated  with  the  cement,  pressed  upon  the  glass  and 
the  excess  of  cement  removed  with  a  suitable  instrument.  The 
cement  dries  rapidly  and  becomes  very  hard. 

Cements  for  Fastening  Metal  Letters  upon  Glass,  Marble,  Wood, 
etc. — I.  Mix  copal  varnish,  15  parts;  boiled  linseed  oil,  5  ;  oil  of 
turpentine,  5  ;  and  glue,  5.  The  glue  is  dissolved  by  placing  the 
mixture  in  a  water  bath.  When  solution  is  complete  10  parts  of 
slaked  lime  are  added. 

II.  Mix  15  parts  of  a  varnish  prepared  from  sandarac  and  white 
resin  with  5  parts  of  linseed  oil,  boiled  with  litharge,  and  5  parts 
of  oil  of  turpentine.  To  this  add  5  parts  of  marine  glue,  and 
after  dissolving  this  mixture  on  a  water  bath  add  10  parts  of  flake 
white  and  white-lead. 

III.  Mix  15  parts  of  copal  varnish  prepared  with  an  addition  of 
resin  and  5  parts  of  oil  of  turpentine  with  2  parts  of  powdered 
isinglass,  5  of  sifted  iron  filings  and  10  of  washed  clay  or  ochre. 

IV.  Mix  15  parts  of  copal  varnish  prepared  with  gum  lac,  5  of 
linseed  oil  boiled  with  litharge,  8  of  solution  of  caoutchouc  in  tar 
oil,  7  of  tar  oil  with  10  of  Roman  cement  and  plaster  of  Paris. 

To  Cement  Glass  into  Metal. — To  cement  the  glass  portions  into 
metallic  cases,  as  is  frequently  required,  for  instance  in  the  manu¬ 
facture  of  physical  and  optical  instruments,  etc.,  the  following 
practically  tested  directions  are  recommended  : 

I.  Melt  carefully  160  parts  by  weight  of  finely  pulverized  colo¬ 
phony,  40  of  white  wax  and  80  of  colcothar ;  add  to  the  melting 


TriE  METAL  WORKER’S  HANDY-BOOK. 


2"G 


mass  20  parts  by  weight  of  Venetian  turpentine,  remove  the  mass 
from  the  fire  and  stir  the  finished  cement  until  cold  with  a  wooden 
spatula.  Apply  the  cement  warm. 

II.  Use  a  good  quality  of  sealing  wax,  which  should,  however, 
not  be  too  brittle.  Any  brittleness  can  be  immediately  removed 
by  the  addition  of  some  Venetian  turpentine.  In  cementing  glass 
into  metallic  cases  the  glass  as  well  as  the  metallic  casing  must  be 
carefully  heated  to  the  melting  point  of  the  sealing  wax. 

III.  Carefully  mix  shellac  with  a  like  quantity  of  finely  powdered 
pumice  and  apply  warm. 

IV.  To  fasten  metallic  or  glass  articles  for  optical  glasses  so  that 
in  polishing  they  remain  in  a  fixed  position  use  a  cement  consisting 
of  a  mixture  of  io  parts  of  pitch  and  i  of  white  wax. 

Cement  for  Fastening  Brass  to  Glass. — For  cementing  brass  on 
glass  the  following  receipt  will  be  found  to  answer  very  well  :  Take 
resin  soap — made  by  boiling  i  part  of  caustic  soda  and  3  parts  of 
resin  in  5  of  water — and  knead  it  into  half  the  quantity  of  plaster 
of  Paris.  This  cement  is  used  largely  for  fastening  the  brass  tops  on 
glass  lamps.  It  is  very  strong,  is  not  acted  upon  by  petroleum, 
bears  heat  very  well  and  hardens  in  one-half  to  three-quarters  of  an 
hour.  By  substituting  zinc  white,  white-lead  or  slaked  lime  for 
plaster  of  Paris  it  hardens  more  slowly.  Water  attacks  only  the 
surface  of  this  cement.  Of  course,  as  it  sets  shortly  after  mixing, 
only  as  much  as  may  be  needed  for  immediate  use  should  be  made 
at  one  time. 

To  Fasten  Leather  upon  Iron. — Apply  a  coat  of  lead  paint,  either 
white  or  red  lead,  to  the  iron.  When  dry  cover  the  coat  of  paint 
with  a  cement  prepared  as  follows  :  Soak  glue  of  the  best  quality 
in  cold  water  until  soft;  then  dissolve  it  in  vinegar  at  a  moderate 
heat,  add  one-third  of  its  volume  of  white  oil  of  turpentine, 
and  after  thoroughly  mixing  apply  the  cement  while  warm  with  a 
brush  and  press  the  leather  upon  it.  Another  method  is  as  follows  : 
Digest  1  part  of  crushed  nut-galls  for  6  hours  with  8  of  distilled 
water  and  strain  the  mass.  Soak  glue  in  its  own  weight  of  water 
for  24  hours  and  then  dissolve  it.  The  warm  infusion  of  galls  is 
spread  upon  the  leather  and  the  glue  solution  on  the  roughened 


CEMENTS. 


237 


surface  of  the  warm  metal ;  the  moist  leather  is  pressed  upon  it  and, 
when  dry,  it  adheres  so  firmly  that  it  cannot  be  removed  without 
tearing. 

To  Fasten  Paper- lab  els  to  Iron. — Rub  the  place  where  the  label 
is  to  be  fastened  with  an  onion  cut  in  half  and  then  stick  on  the 
label  with  paste,  gum  or  glue.  The  vegetable  mucilage  of  the 
onion  adheres  firmly  to  the  iron  and  combines  with  the  paste  on 
the  paper  to  a  mass  which  does  not  crack  off  and  stands  heating. 

Cement  for  Fastening  Labels  on  Polished  Nickel. — Dissolve  400 
parts  by  weight  of  coarsely  powdered  dextrin  in  600  of  water,  add 
20  of  glycerin  and  10  of  glucose  and  heat  the  mixture  to  1940  F. 

Another  Mode  of  Preparation  is  as  follows:  Stir  400  parts  by 
weight  of  dextrin  with  water,  dilute  the  mass  by  a  further  addition 
of  200  parts  by  weight  of  water,  add  20  of  glucose  and  10  of 
aluminium  sulphate  and  heat  the  mass  in  a  steam-bath  to  1940  F., 
whereby  the  mass,  which  is  at  first  thick,  becomes  clear  and  thinly 
fluid.  Both  kinds  of  cement  are  well  suited  for  the  purpose, 
though  the  first  deserves  the  preference. 

To  Cement  Forks  and  Knives  in  their  Handles. — I.  Mix  1  part 
of  brickdust  and  2  of  pulverized  colophony.  Fill  the  cavity  in  the 
handle  with  the  mixture  and  push  in  the  previously  heated  tang  of 
the  blade. 

II.  Melt  together  4  parts  of  colophony  and  1  part  of  sulphur 
and  stir  into  the  melted  mass  iron  filings,  fine  sand  or  brick-dust. 
Use  in  the  same  manner  as  in  I. 

III.  To  Secure  Forks  and  Knives  in  Silver  Handles. — Melt  2 
parts  of  pitch  and  stir  1  part  of  brickdust  into  the  melted  mass. 
Fill  the  cavity  in  the  handle  with  the  mixture  and  push  in  the  tang 
of  the  blade. 

To  Cement  with  Copper  Amalgam. — The  metals  to  be  cemented 
are  first  made  bright  by  acid,  then  heated  to  from  176°  to  1940  F. 
and,  after  applying  the  amalgam,  firmly  pressed  together.  The 
parts  adhere  as  firmly  as  if  soldered. 

Ce7nents  for  Parts  of  Machines. — These  consist  of  a  mixture  of 
caoutchouc  or  gutta-percha  with  filings  of  iron,  steel,  copper  or 
brass,  or,  in  the  place  of  the  latter,  with  powdered  iron  or  copper 


238 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


ores.  The  caoutchouc  and  gutta-percha  form  either  essential  parts 
of  the  mixture  or  simply  serve  for  cementing  the  metallic  sub¬ 
stances  together.  An  addition  of  sal-ammoniac  or  another  sub¬ 
stance,  which  attacks  the  metals  in  the  presence  of  water,  serves 
for  the  oxidation  of  the  metals  in  the  mixture,  thus  effecting  a 
firmer  union.  The  ingredients  may,  if  desired,  be  compounded 
with  sulphur  combinations ;  they  are  then  rolled  out  and  brought 
into  the  required  shape.  The  proportions  vary  according  to  the 
purpose  for  which  the  cement  is  to  be  used. 

I.  For  Steam- Pipes. — Caoutchouc,  2  parts ;  gutta-percha,  1  ; 
sulphur,  1 ;  iron  filings,  10.  Should  there  be  a  difference  in  price, 
a  portion  of  the  caoutchouc  may  be  replaced  by  gutta-percha  and 
vice  versa  ;  powdered  ores,  with  omission  of  a  corresponding  por¬ 
tion  of  sulphur,  may  be  substituted  for  the  portion  of  the  iron 
filings. 

II.  Cement  for  Parts  of  Copper  and  Brass. — The  same  composi¬ 
tion  as  given  under  I.  is  used,  the  iron  being  replaced  by  copper  or 
brass  shavings. 

III.  For  Pipe-conduits  not  Exposed  to  Heat. — Caoutchouc,  4 
parts  ;  gutta-percha,  1  ;  sal-ammoniac,  1  ;  sulphur,  1  ;  iron  fil¬ 
ings,  10. 

IV.  For  Packing  Stuffing-boxes  and  Pistons  of  Steam-engines. — 
Caoutchouc,  5  parts ;  gutta-percha,  2  ;  sulphur,  1  ;  powdered 
graphite,  1  ;  silicate  of  magnesia,  1  ;  filings  of  copper,  zinc,  lead, 
tin  or  alloys  of  these  metals,  10. 

If  the  ingredients  have  been  intimately  mixed  and  form  a  homo¬ 
geneous  mass  the  cements  are  well  adapted  for  the  purposes  men¬ 
tioned.  If  one  of  the  cements  is  to  be  exposed  to  the  direct  action 
of  the  fire  or  a  high  degree  of  heat  asbestos  is  to  be  added  to  the 
mixture.  For  the  oxidation  of  the  metals  contained  in  the  cements 
they  are  exposed  to  the  action  of  cold  or  hot  water  for  1  to  12 
hours,  according  to  the  thickness  of  the  plates  into  which  they 
have  been  rolled.  The  penetration  of  moisture  into  the  mass  is 
promoted  by  mixing  with  it  some  fibrous  material  such  as  cotton  or 
asbestos. 

A  Permanent  and  Durable  foint  can  be  made  between  rough 


CEMENTS. 


239 


cast-iron  surfaces  by  the  use  of  mineral  asbestos  mixed  with  suf¬ 
ficient  white-lead  to  make  a  very  stiff  putty.  This  will  resist  any 
amount  of  heat,  and  is  unaffected  by  steam  or  water.  It  has  been 
employed  for  mending  or  closing  cracks  in  cast-iron  retorts  used  in 
the  distillation  of  oil  and  gas  from  cannel  coal.  The  heat  being 
applied  to  the  bottom  of  the  retorts,  and  the  temperature  of  the  iron 
maintained  at  a  bright  red  heat,  after  a  time  the  bottom  of  the  retort 
would  give  way,  the  larger  portion  of  the  crack  being  downward 
toward  the  fire.  The  method  employed  was  to  prepare  the  mixture 
and  place  it  on  the  top  of  a  brick,  then  put  the  brick  on  a  bar  of 
iron  or  a  shovel,  and  press  the  cement  upward  to  fill  the  crack  in 
the  iron,  holding  it  for  some  time  until  it  had  penetrated  the  cavity 
and  somewhat  set.  Of  course,  during  this  operation,  the  lid  was 
removed  from  the  retort,  so  that  no  pressure  of  gas  or  oil  forced 
the  cement  outward  until  set. 

Schiefer' s  Packing  Rings  for  Manholes  and  Flanges. — The  joining 
of  manholes  and  flanges  is  not  difficult  when  there  is  sufficient 
time  to  allow  the  cement  to  harden.  The  case  is,  however,  dif¬ 
ferent  when  such  joints  are  to  be  made  in  a  short  time  and  the 
work  is  to  be  at  once  proceeded  with.  Hence  the  use  of  Schiefer’s 
rings  may  be  recommended,  which  avoid  this  evil  and  allow  of  an 
immediate  continuation  of  the  work.  The  rings  are  made  of  stout 
pasteboard,  and  receive  first  a  ground  paint  of  ioo  parts  of 
graphite,  ioo  of  fibrous  gypsum,  2  of  alum,  and  20  of  rye  flour  in 
75  of  water.  The  mass  is  intimately  and  finely  ground,  and 
applied  thrice  as  uniformly  as  possible  to  the  rings.  The  rings 
when  completely  dry  and  hard  and  solid  are  again  three  times 
coated  with  a  paint  of  50  parts  of  graphite,  5  of  chemically  pure 
white-lead,  of  borate  of  manganese  and  20  of  good  linseed  oil 
varnish,  and  are  then  ready  for  use.  They  are  then  again  coated 
with  the  above  composition,  which  should,  however,  be  of  greater 
consistency  and  are  used  in  the  same  manner  as  rubber  or  similar 
rings. 

Colored  Cement  for  Repairing  Zinc  Ornaments.- — Soda  water  glass 
solution  of  330  Be  is  intimately  mixed  with  fine  whiting  and  an 
addition  of  zinc  dust  (tutty)  to  a  thick  plastic  mass,  which  hardens 


240 


THE  METAL  WORKER’S  HANDY-BOOK. 


in  6  to  8  hours,  becomes  extraordinarily  solid  and  acquires  a  gray 
color.  By  polishing,  after  hardening,  with  an  agate  it  acquires  the 
lustrous  white  color  of  metallic  zinc,  so  that  defective  zinc  orna¬ 
ments  and  zinc  vessels  can  be  durably  repaired  with  it.  The 
cement  adheres  well  also  to  glass  and  wood. 

Evans' s  Metallic  Cement. — This  alloy  is  obtained  by  dissolving 
cadmium  amalgam  prepared  from  25.99  parts  of  cadmium  and 
74.01  parts  of  mercury  in  an  excess  of  mercury,  slightly  pressing 
the  solution  in  a  leather  bag  and  thoroughly  kneading.  By  knead¬ 
ing,  especially  if  previously  heated  to  about  970  F.,  the  cement  is 
rendered  very  plastic  and,  like  softened  wax,  can  be  brought  into 
any  form.  On  cooling  it  acquires  considerable  hardness. 

Cement  for  Luting  Crucible  Lids. — Apply  a  thick  paste  made 
from  lime  freshly  slaked  to  a  powder  and  concentrated  solution 
of  borax.  Let  it  dry  slowly  and  then  heat  in  the  usual  manner. 

Cements  for  Water-pipes. — I.  Cement  for  Joinitig  Cast-iron  Water- 
pipes  (for  use  on  a  large  scale).  Pulverize  and  mix  24  parts  of 
Roman  cement,  8  of  white  lead,  2  of  litharge  and  1  of  colophony. 
Work  the  mixture  into  a  plastic  mass  with  old  linseed  oil  kept 
boiling  together  with  one-half  its  weight  of  colophony  until  the 
latter  is  dissolved. 

II.  Mix  equal  parts  of  burned  lime,  Roman  cement,  potter’s 
clay  and  clay,  all  separately  dried  and  ground  fine,  and  knead  the 
mixture  with  linseed  oil. 

III.  Melt  together  colophony  and  tallow,  and  stir  into  the 
melted  mass  enough  finely  sifted  gypsum  to  give  it  the  required 
consistency. 

Bismuth  Cement  for  Cementing  the  Glass  Parts  on  Petroleum 
Lamps. — This  cement  is  composed  of  lead,  3  parts  ;  tin,  2  ;  and 
bismuth,  2.5. 

Armenian  or  Jeweller' s  Cement. — Dissolve  5  or  6  pieces  of  gum 
mastic  the  size  of  a  large  pea  in  as  much  spirits  of  wine  as  will 
suffice  to  render  it  liquid ;  in  a  separate  vessel  dissolve  as  much 
isinglass  (previously  softened  in  water,  though  none  of  the  water 
must  be  used)  in  rum  or  other  spirit,  as  will  make  a  2  oz.  phial  of 
very  strong  glue,  adding  two  small  pieces  of  gum-ammoniac,  which 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


241 


must  be  rubbed  or  ground  until  dissolved,  then  mix  the  whole 
at  a  sufficient  heat.  Keep  it  in  a. phial  closely  stoppered,  and 
when  it  is  to  be  used  set  the  phial  in  boiling  water.  This  cement 
is  effectual  in  uniting  almost  all  substances,  even  glass  to  polished 
steel. 


IX. 

CLEANSING,  GRINDING,  PICKLING,  POLISHING. 

Cleansing  Metals  with  the  Sand  Blast. — In  large  establishments 
engaged  in  galvanizing  cast-iron  without  previous  grinding,  the  use 
of  the  sand  blast  in  place  of  the  circular  wire  brush  has  recently 
been  introduced  with  great  advantage.  Articles  with  deep  depres¬ 
sions,  which  cannot  be  reached  with  the  scratch-brush,  as  well  as 
small  articles,  which  cannot  be  conveniently  held  in  the  hand  and 
pressed  against  the  revolving  scratch-brush,  can  only  be  brought 
by  the  sand  blast  into  a  state  of  sufficient  metallic  purity  for  the 
galvanizing  process.  However,  while  the  revolving  scratch-brushes 
impart  to  the  objects  a  certain  lustre,  they  acquire  by  the  sand 
blast  a  dead  lustre  and,  hence,  the  blast  is  also  frequently  used  for 
the  purpose  of  deadening  lustrous  surfaces  to  their  entire  extent,  or 
of  producing  contrasts ;  for  instance,  dead  designs  upon  a  lustrous 
ground,  or  vice  versa. 

Fig.  7  shows  such  a  sand  blast.  The  compressed  air,  whose 
pressure  must  be  at  least  equal  to  an  18^-inch  column  of  water, 
passes  through  the  blast-pipe  A  into  a  nozzle  running  horizontally 
through  the  machine,  and  carries  away  from  there  a  jet  of  sand 
which  falls  into  the  outflowing  blast,  and  is  hurled  upon  the  objects 
placed  under  the  nozzle.  The  objects  rest  upon  sheet-iron  plates 
or  in  boxes  of  sheet-iron,  which,  moving  at  a  slow  rate,  pass  under 
the  nozzle ;  the  motion  is  effected  by  the  shafts  B  B  with  the  use 
of  rubber  belts.  To  prevent  dust  the  machine  is  provided  with  a 
wooden  or  sheet-iron  casing,  a  few  windows  allowing  a  view  of 
the  interior.  The  sand  used  in  blasting  collects  in  a  box  and  is 
returned  to  the  sand-reservoir  by  an  elevator. 

16 


242 


THE  METAL  WORKER’S  HANDY-BOOK. 


The  jet  of  sand  acts  not  only  upon  the  upper  side  of  the  objects, 
which  it  strikes  first,  but  also  almost  as  energetically  upon  the 
lower,  so  that,  as  a  rule,  the  cleansing  process  is  completed  by 
one  operation.  Articles  of  a  specially  unfavorable  shape  must  be 
passed  twice  or  three  times  under  the  nozzle. 


F'g-  7- 


Cleansing  of  Metals  by  Means  of  Acids  with  the  Use  of  a  Galvanic 
Current. — When  metallic,  especially  iron,  objects  are  cleansed  and 
made  bright  by  pickling  in  an  acid,  the  latter,  as  a  rule,  dissolves 
besides  the  oxide  more  or  less  metal,  whereby  the  surface  of  the 
article  loses  much  of  its  smoothness.  To  avoid  this,  the  articles  to 
be  cleansed  are  made,  while  being  immersed  in  the  acid  mixture, 
the  negative  pole  of  a  galvanic  apparatus,  whereby  the  metal  is 
almost  completely  protected.  For  this  purpose  a  square  vessel  is 
used,  in  the  centre  of  which  stand  two  narrow,  porous  cells.  Each 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


243 


of  these  cells  contains  a  number  of  zinc  plates  fastened  to  an  iron 
rod  above  the  cell.  In  the  vessel,  on  the  side  of  each  cell,  is  a 
movable  bottom  provided  with  holes,  upon  the  upper  surface  of 
which  is  secured  an  iron  bar  bent  to  and  fro.  This  bar  is  connected 
by  a  wire  to  the  rod,  to  which  are  suspended  the  zinc  plates  of  the 
corresponding  cell.  For  use,  the  vessel  and  the  cells  are  filled  as 
full  as  possible  with  a  fluid  consisting  of  i  lb.  of  common  salt,  5 
lbs.  of  water,  and  26  ozs.  of  sulphuric  or  hydrochloric  acid.  The 
articles  to  be  cleansed  are  placed  upon  the  above-mentioned  bot¬ 
toms,  whereby  they  come  in  contact  with  the  iron  bars,  and  become 
the  negative  pole  of  a  simple  galvanic  apparatus.  The  cleansing 
action  of  the  fluid  is,  if  necessary,  assisted  by  heating  by  means  of 
a  steam-pipe  placed  at  the  bottom  of  the  vessel. 

Scouring  and  Polishing  of  Knitting  Needles. — For  this  purpose 
Kraiten  &  Schneeloch,  of  Altena,  Westphalia,  use  a  four-cornered 
box,  the  length  of  the  knitting  needles.  The  long  sides  of  this 
box,  from  about  yi  their  height,  run  obliquely,  with  an*inclination 
of  40°  towards  the  interior.  On  the  oblique  sides  inside  of  the  box 
move  up  and  down  two  flat  wedges,  which  above  are  connected  by 
joints  to  vertical  rods.  On  top  these  rods  run  in  guides,  and  are 
moved  up  and  down  by  a  crank  with  connecting  rod.  Between  the 
two  flat  wedges  the  box  is  filled  with  about  55  lbs.  of  knitting 
needles,  a  few  handfuls  of  comminuted  pebbles,  and  about  1  quart 
of  oil.  The  oblique  sides  force  the  wedges  in  passing  down  to 
move  towards  the  interior,  whereby  the  knitting  needles  and 
pebbles  are  rubbed  together,  scouring  the  former  bright.  To  pre¬ 
vent  some  of  the  knitting  needles  slipping  between  the  wedges  and 
the  walls  of  the  box,  springs  are  placed  on  the  stationary  guides, 
which  press  the  wedges  against  the  oblique  sides. 

To  Scoter  and  Polish  Needles. — Needles  of  equal  length,  but  of 
varying  thickness,  are  placed  parallel  and  in  7  or  8  rows  lengthwise 
upon  close,  coarse  linen,  and  covered  alternately  with  thin  layers 
of  fine  quartz  sand  or  emery  powder.  Rape-seed  oil  is  then  poured 
over  the  mass,  and  the  whole  rolled  together  in  the  form  of  a 
sausage.  These  rolls  are  about  17^  to  23^  inches  long,  3  to  5 
inches  thick,  and  contain  from  150,000  to  500,000  needles.  They 


244 


THE  METAL  WORKER’S  HANDY-BOOK. 


are  tied  together  on  the  ends,  and  sometimes  wrapped  around  with 
a  stout  cord  ;  1 2  to  40  of  them  are  then  placed  one  after  the  other 
in  the  scouring  mill.  The  latter  consists  essentially  of  a  lower  and 
upper  wooden  plate,  one  of  which  is  fluted  and  can  be  moved  to 
and  fro.  When  the  lower  plate  is  stationary,  the  whole  resembles 
an  ordinary  mangle,  and  it  acts  also  in  a  similar  manner,  the  rolls 
containing  the  needles  being  set  in  a  rolling  motion  by  the  moving 
to  and  fro  of  the  fluted  plate.  By  these  means  the  needles  rub 
against  each  other,  and  are  scoured  and  polished  in  the  sharp 
sand. 

To  Cleanse  Guns  with  Petroleum. — Cleansing  a  weapon  with  fats 
and  oils  does  not  entirely  protect  it  from  rust ;  the  so-called  drying 
oils  get  gummy  and  resinous,  while  the  non-drying  oils  become 
rancid,  and  by  exposure  to  the  air  acids  are  formed,  and  these 
attack  the  iron.  For  these  reasons  petroleum  is  to  be  preferred  for 
this  purpose.  Petroleum  is  as  great  an  enemy  to  water  as  are  the 
fatty  oils, *and  hence  it  keeps  away  the  water  from  a  gun-barrel 
covered  with  it.  It  is  very  essential,  however,  that  the  petroleum 
employed  be  perfectly  pure,  for  impure  oil,  such  as  is  often  met 
with  in  commerce,  attacks  the  metal.  Care  must  also  be  had  not 
to  allow  it  to  come  in  contact  with  the  polished  stock.  When 
about  to  clean  a  gun,  some  tow  is  wrapped  around  the  ramrod  and 
enough  petroleum  poured  upon  it  to  thoroughly  moisten  it ;  it  is  then 
pushed  in  a  rotary  manner  through  the  barrel  and  back  a  dozen 
times,  and  the  tow  taken  out  and  unrolled,  and  the  upper  and  lower 
ends  of  the  barrel  rubbed  with  the  clean  part,  after  which  it  is 
thrown  away.  This  removes  the  coarser  portion  of  the  dirt.  A 
round  brush  of  stiff  bristles,  and  fitting  the  barrel,  is  now  screwed 
to  the  ramrod,  then  moistened  thoroughly  with  petroleum  and 
twisted  into  the  barrel,  running  it  back  and  forth  at  least  a  dozen 
times,  thus  loosening  the  dirt  that  is  more  firmly  attached.  The 
first  operation  is  now  repeated,  except  that  the  tow  on  the  ramrod 
is  left  dry,  and  the  rubbing  with  this  must  be  continued  in  all  direc¬ 
tions  as  long  as  it  comes  out  soiled.  The  use  of  wire-brushes  is 
objectionable  for  cleaning  guns,  as  the  numerous  steel  points  cut 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


245 


into  the  tube.  Only  soft  tow,  hemp,  woollen  rags,  or  the  like, 
should  be  used,  as  the  petroleum  dissolves  the  dirt  sufficiently. 

Cleansing  of  Coins,  Medals,  and  Articles  of  Silver. — Rossler 
recommends  for  this  purpose  a  moderately  concentrated  solution  of 
potassium  cyanide,  kept  ready  for  use  in  a  bottle.  In  cleansing 
medals  and  smaller  objects  place  three  tumblers  alongside  each 
other,  two  of  them  filled  with  water  and  one  with  solution  of  potas¬ 
sium  cyanide.  Now  grasp  the  objects  separately  with  brass 
tweezers,  and  dip  them  in  the  potassium  cyanide  solution;  the 
brownish  or  dirty  yellow  coating  disappearing  at  once.  Then  rinse 
the  objects  quickly  in  the  second  and  third  tumblers,  and  finally 
dry  them  with  a  linen  cloth.  Larger  articles — for  instance,  spoons, 
tankards,  candlesticks,  etc. — are  treated  by  moistening  the  yellow 
places  with  a  small  brush  or  tuft  of  cotton  saturated  with  solution 
of  potassium  cyanide,  washing  and  drying.  The  process  is  used 
in  the  same  manner  for  gilded  articles. 

To  Cleanse  Golden-bronze. — Bronze  which  has  become  dirty  by 
oil,  fat,  tallow,  or  other  greasy  body,  is  boiled  in  an  infusion  of 
ashes,  and  cleansed  with  a  soft  brush  dipped  in  a  fluid  of  equal  parts 
of  water,  nitric  acid,  and  alum.  Each  piece  is  then  dried  with  a 
rag,  and  slightly  heated.  To  cleanse  clock  pendulums,  and  free 
them  from  the  substance  called  by  the  gilders  “mercury-dust,”  heat 
them  moderately,  touch  the  stain  with  a  brush  dipped  in  nitric  acid, 
rub  with  a  linen  rag,  and  again  heat  moderately. 

To  Cleanse  Bronze  Fixtures. — Boil  the  articles  in  ordinary  soap¬ 
boilers’  lye,  rinse  in  water,  and  roll  in  bran  or  sawdust.  If  the 
bronze  is  pressed,  the  lye  must  be  mixed  with  common  salt  and 
the  article  thoroughly  brushed,  but  no  water  must  touch  the 
back. 

To  Cleanse  Silvered  Dial-plates. — Silvered  dial-plates  of  clocks 
frequently  lose  their  lustre  by  the  effect  of  air  and  smoke  or  sul¬ 
phurous  emanations.  To  cleanse  them  make  pulverized  purified 
tartar  into  a  paste  with  water.  Take  some  of  the  paste  on  a  brush 
of  bristles  and  rub  the  dial-plate,  turning  it  constantly  until  the 
silvering  has  acquired  its  original  whiteness  and  lustre.  Then  wash 


246 


THE  METAL  WORKER’S  HANDY-BOOK. 


the  dial-plate  with  clean  water  and  dry  by  gently  patting  with 
cloth,  and  finally  expose  it  for  a  few  minutes  to  a  moderate  heat. 

To  Cleanse  Chandeliers  and  Gas-fixtures. — The  chandeliers  or 
fixtures,  whether  gilded  or  not,  are  taken  apart  and  the  separate 
parts  boiled  for  a  few  minutes  in  a  sharp  lye  and  then  cleansed  with 
a  soft  brush.  Next  draw  them  through  a  strong  solution  of  potas¬ 
sium  cyanide,  then  wash  them  in  a  large  boiler  with  hot  water,  dry 
them  in  clean  saw-dust  and  finally  polish  them  with  chamois 
leather.  If  necessary,  lacquer  the  parts  after  putting  them  to¬ 
gether. 

To  Clean  Small  Screws. — Screws  that  are  too  small  for  separate 
treatment  may  be  cleaned  from  rust  as  follows:  Take  a  pound  of 
strews  and  place  them  in  a  small  box — a  cigar-box  will  do ;  put  a 
small  quantity  of  oil  on  them  and  shake  for  a  minute.  Then  put  a 
piece  of  cotton-waste  in  the  box  and  repeat  shaking  for  a  minute  ; 
finally  put  a  handful  of  saw-dust  in  the  box  and  shake  for  another 
minute  or  so  and  remove  the  saw-dust  by  sifting  it  from  the  screws 
in  a  fine  sieve. 

To  Free  Iron  from  Ingrained  Rust. — A  thorough  cleansing  of  the 
iron  may  be  easily  effected  by  immersing  the  article  in  a  nearly 
saturated  solution  of  chloride  of  tin.  The  duration  of  the  immer¬ 
sion  will  depend  upon  the  thicker  or  thinner  film  of  rust ;  in  most 
cases,  however,  12  to  24  hours  will  suffice.  The  solution  of 
chloride  of  tin  must  not  contain  too  great  an  excess  of  acid,  other¬ 
wise  it  will  attack  the  iron  itself.  After  the  articles  have  been  re¬ 
moved  from  the  bath  they  should  first  be  washed  in  water  and  then 
with  ammonia  and  be  dried  as  quickly  as  possible.  Articles  which 
have  been  treated  in  this  manner  assume  the  appearance  of  dead 
silver,  but  their  normal  appearance  may  be  restored  by  simple 
polishing. 

To  Remove  Rust  from  Polished  Steel  A  rticles.  — Soak  the  rusty  places 
for  a  few  days  with  oil  and  then  scour  with  emery  or  tripoli  and  oil, 
using  a  stick  of  hard  wood.  Wipe  off  the  oil  and  all  other  im¬ 
purities,  rub  the  stains  once  more  with  emery  and  wine  vinegar  and 
finally  polish  with  fine  bloodstone  and  leather. 

To  Extract  Rust  from  Steel. — Immerse  the  article  to  be  cleaned 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


247 


for  a  few  minutes,  until  all  dirt  and  rust  is  taken  off,  in  a  strong 
solution  of  cyanide  of  potassium,  say  about  oz.,  in  a  wineglass¬ 
ful  of  water;  then  take  it  out  and  clean  it  with  a  tooth-brush 
dipped  into  a  composition  of  cyanide  of  potassium,  castile  soap, 
whiting  and  water  made  into  a  paste  of  about  the  consistency  of 
cream. 

To  Remove  Rust  from  Nickel-plated  Articles. — Grease  the  rust 
stains  and  after  a  few  days  rub  thoroughly  with  a  cloth  moistened 
with  ammonia.  The  ammonia  dissolves  the  rust  without  injury  to 
the  plating.  Should  this  process  be  not  entirely  successful,  touch 
the  stains  with  dilute  hydrochloric  acid  and  rub  vigorously.  Then 
wash  the  articles  and  when  dry  polish  with  tripoli  or  a  similar 
polishing  material. 

To  Freshen  up  Nickel  Watch-movements. — Nickel  watch-move¬ 
ments  which  have  become  yellow  or  stained  by  reason  of  change 
of  temperature  or  other  influences  may  be  freshened  up  as  follows : 
To  50  parts  of  rectified  alcohol  add  1  part  of  sulphuric  acid. 
Place  the  parts  to  be  freshened  in  this  fluid  for  10  to  15  seconds, 
immersing,  however,  only  a  few  at  a  time,  so  as  to  be  able  to  take 
them  out  at  the  proper  time,  since  a  longer  immersion  would  be 
injurious.  When  taken  from  the  fluid  rinse  the  parts  in  clean 
water  and  then  place  them  for  a  short  time  in  rectified  alcohol ; 
finally  dry  them  in  saw-dust  or  with  soft  linen.  Nickel  movements 
thus  cleaned  have  almost  the  appearance  of  being  new,  their 
smoothness  being  not  in  the  slightest  degree  injured,  as  would  be 
the  case  if  the  leather-file  or  brush  were  used. 

Grinding. — -The  object  of  grinding  metallic  surfaces  is  the  same 
as  that  of  filing  and  consists  in  the  removal  from  the  surface  of  very 
fine  particles  by  the  rough  grains  of  the  grinding  agents.  Metals 
which  are  to  be  ground  show,  as  a  rule,  a  very  rough  surface,  it 
not  being  possible  to  obtain  another  one  in  casting,  forging,  ham¬ 
mering,  etc.  The  object  of  grinding  is  to  give  shape  to  the  article 
or  beautify  its  surface,  and  the  principal  condition  for  executing 
the  grinding  process  is  that  the  grinding  material  should  under  all 
circumstances  be  harder  than  the  article  to  be  ground,  it  being  of 
no  consequence  whether  it  is  used  in  a  solid  form  (stones  or  wheels) 


248 


TITE  METAL  WORKER’S  IIANDY-BOOK. 


or  as  a  powder.  The  choice  of  the  grinding  material  depends  en¬ 
tirely  on  the  nature  and  condition  of  the  article  to  be  ground. 
Grindstones,  for  instance,  attack  hardened  steel  articles  much  bet¬ 
ter  than  even  the  best  files.  The  health  of  the  workman  being 
much  affected  by  dry-grinding,  it  is  now  chiefly  used  only  for 
such  articles  which,  for  instance,  like  needles,  cannot  be  con¬ 
veniently  dried  separately,  but  nevertheless  suffer  much  from  rust. 
The  fine  particles  of  iron  and  stone  which  become  detached  are 
best  removed  by  a  small,  rapidly-running  ventilator.  In  wet-grind¬ 
ing  the  lower  half  of  the  stone  runs  either  in  water  or  is  kept  wet 
from  above  by  a  gutter ;  it  has  the  advantage  of  not  wearing  out 
the  stone  so  quickly,  of  producing  finer  and  more  uniform  grinding 
scratches  upon  the  articles  and  heating  them  less,  which  is  of 
special  importance  in  grinding  hardened  steel.  Small  grind¬ 
stones  are  generally  driven  by  hand,  but  larger  ones  by  power  ; 
special  contrivances  for  securing  the  article  to  be  ground  are 
also  frequently  used.  In  grinding  with  pulverulent  substances 
the  article  to  be  ground  remains  either  stationary  or  is  made  to  re¬ 
volve,  the  grinding  agent  being  pressed  against  it  by  the  hand  or  a 
special  contrivance.  Generally  speaking,  it  is  the  same  whether 
the  grinding  material  is  moved  over  the  article  or  the  latter  over 
the  former,  but  mostly  the  article  to  be  ground  is  held  firmly  or 
moved  very  slowly,  while  the  grinding  agent,  for  instance  the 
grindstone,  wheels  coated  with  grinding  powder  and  similar  con¬ 
trivances,  revolve  very  rapidly.  Grinding  may  also  be  effected  by 
the  sand-blast ;  this  process  is  now  much  used  for  cleansing  cast¬ 
ings,  etc. 

Rules  for  the  Use  of  Emery  Wheels. — In  using  emery  wheels  the 
following  rules  are  to  be  observed:  x.  To  make  the  most  of  the  use 
of  emery  wheels,  a  strongly  built  grinding  machine  upon  a  solid 
foundation  is  the  principal  condition.  2.  The  wheel  must  not  be 
forced  or  wedged  upon  the  grinding  shaft,  but  must  easily  fit  upon 
it.  For  this  purpose  it  is  recommended  to  have  the  diameter  of  the 
wheel-base  at  least  0.039  ’nc^  larger  than  the  diameter  of  the  axis. 
3.  Place  between  the  iron  flanges,  which  should  be  about  one-third 
the  diameter  of  the  wheel,  and  the  sides  of  the  wheel  a  disk  of 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


249 


pasteboard  or  rubber  about  0.079  inch  thick.  4.  The  loose 
flange  should  not  be  screwed  up  tighter  than  can  be  done  with  a 
wrench  with  one  hand.  With  thin  wheels,  especially  those  for 
sharpening  saws,  the  nut  must  be  very  moderately  tightened,  and 
it  is  best  to  fix  it  with  a  jam-nut.  5.  It  is  advisable  in  grinding  to 
press  whenever  possible  with  the  entire  hand,  since  in  free-hand 
grinding  even  the  hardest  wheel  breaks  from  the  unequal  pressure. 
Unskilled  grinders  should  whenever  possible  use  an  adjustable  table. 
6.  The  emery  wheel  is  to  be  protected  from  every  shock,  and  the 
maximum  number  of  revolutions  must  not  be  exceeded.  7.  When 
a  wheel  has  lost  its  round  shape  it  should  be  at  once  turned  by 
means  of  a  diamond  or  other  suitable  tool,  as  otherwise  the  efficacy 
of  the  wheel  is  not  completely  utilized,  and  the  irregular  running 
may  cause  it  to  burst.  In  turning  the  wheel  by  means  of  a 
diamond,  it  must  be  revolved  by  hand  or  placed  in  a  lathe. 

Emery  Wire  is  a  thick  or  thin  wire  which  is  made  sharp  by  oiling 
and  then  scattering  emery  over  it ;  it  is  used  either  in  a  form 
similar  to  a  drill-bow  or  in  the  same  manner  as  an  emery  belt  run¬ 
ning  over  pulleys.  The  wire  may  also  be  made  sharp  by  allowing 
it  to  run  first  through  a  vessel  filled  with  oil  and  then  through  one 
filled  with  emery  powder,  by  which  means  there  is  always  fresh 
emery  for  grinding. 

Emery  Sticks  are  file-like  instruments  used  for  working  the 
various  metals,  as  well  as  other  substances,  and  which  in  certain 
cases  may  replace  steel  files.  They  are  either  round,  pointed  on 
one  end,  or  uniformly  flat  or  angular,  and  consist  either  through  and 
through  of  a  composition  similar  to  that  used  for  emery  wheels, 
or  they  are  of  wood,  coated  with  a  thin  layer  of  the  above- 
mentioned  composition,  or  they  consist,  finally,  of  emery  paper 
pasted  on  wood.  The  manufacture  of  the  first  kind  is  similar  to 
that  of  emery  wheels.  For  making  the  second  kind,  the  wood  may 
be  coated  with  a  solution  of  shellac  in  alcohol,  and  the  emery 
applied  before  the  shellac  is  entirely  dry ;  the  whole  is  then  dried 
thoroughly.  This  coating  with  shellac  and  emery  has  to  be  several 
times  repeated,  until  the  layer  is  of  sufficient  thickness.  Care  must 
be  had  to  allow  each  application  of  shellac  solution  and  emery  to 


250 


TITE  METAL  WORKER’S  IIANDY-BOOK. 


become  thoroughly  dry  before  applying  the  next,  as  otherwise  the 
mass  remains  soft,  and  readily  rubs  off.  To  make  the  third  kind  of 
emery  stick,  the  wood  to  be  used  must  be  very  dry  and  smoothly 
planed.  Coat  it  first  a  few  times  with  thin  glue  solution,  and  then 
rub  it  smooth  with  glass  paper;  cut  the  emery  paper  into  suitable 
pieces,  and,  after  coating  the  back  with  boiling  glue,  stick  it  on 
the  prepared  wood,  being  careful  to  have  it  perfectly  smooth. 

To  Cleanse  Emery  which  has  been  Used. — Formerly  emery  which 
had  been  used  was  considered  useless  waste,  though  sometimes 
attempts  were  made  to  make  it  again  available  by  glowing  it,  in 
order  to  destroy  the  admixed  oil.  But  other  impurities  were  not 
removed  by  this  treatment,  while,  on  the  other  hand,  the  emery 
lost  its  hardness.  The  oil  and  other  impurities  can,  however,  be 
removed  from  the  emery  without  injuring  its  hardness,  as  follows: 
Boil  the  emery  with  a  sufficient  quantity  of  caustic  soda  solution  of 
specific  gravity  1.015,  in  order  to  extract  and  saponify  the  oil  and 
fat ;  this  is  effected  in  a  cast-iron  boiler,  and  by  keeping  the  emery 
as  much  as  possible  suspended  in  the  fluid  by  means  of  a  stirring 
apparatus.  After  the  saponification  of  the  oil,  the  fluid  is  drawn 
off  into  another  vessel ;  it  may  then  be  mixed  with  acid  to  separate 
the  fatty  acids  formed,  which,  after  washing,  can  be  used  for  various 
purposes.  To  the  emery  remaining  in  the  boiler,  water  is  added, 
and  the  stirring  apparatus  again  set  in  motion  to  wash  out  the 
admixed  impurities.  The  emery  is  finally  dried  and,  if  it  does  not 
contain  too  much  iron,  is  again  available.  If,  however,  it  contains 
a  large  quantity  of  iron,  it  is,  after  drying,  allowed  to  slide  down  an 
inclined  plane  along  which  electro-magnets  are  placed,  which  retain 
the  iron  particles.  The  emery  may,  however,  also  be  treated  with 
hydrochloric,  sulphuric,  nitric  acids,  etc.,  to  dissolve  the  iron. 
The  emery  freed  from  iron  is  washed  and  dried,  and,  if  it  should 
contain  much  sand,  freed  from  it  by  winnowing. 

Pickling  or  Dipping  of  Metallic  Objects. — Metallic  objects  are  ren¬ 
dered  bright  by  removing  the  oxides  with  an  acid.  For  cast-iron 
or  wrought-iron  articles  mix  1  part  of  sulphuric  or  hydrochloric  acid 
with  10  parts  of  water,  add  some  tar,  and  immerse  the  objects  in 
the  mixture  until  the  scales  are  removed  from  the  surface,  after 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


251 


which  they  are  rinsed  off  in  clean  water  and  dried.  The  purpose 
of  pickling  copper ,  brass,  tombac,  and  bronze  is  to  produce  a  lustrous 
surface.  Finished  brass  sheets,  after  passing  through  the  rolls, 
have  a  black  color,  which  is  partially  due  to  the  formation  of 
cupric  oxide  on  the  surface,  and,,  partially,  to  sulphur  combinations 
formed  by  heating  with  coal  in  annealing.  In  order  to  impart  to 
the  brass  its  characteristic  beautiful  yellow  color  it  is  subjected  to 
pickling.  The  operation  commences  by  placing  the  sheets  in  a 
fluid  consisting  of  io  parts  of  water  and  i  of  sulphuric  acid.  The 
layer  of  oxide  quickly  dissolves,  and  the  sheets  show  the  pure,  yel¬ 
low  brass  color ;  they  are  then  washed  and  dried.  In  most  cases 
the  sheets  are  subjected  to  a  second  treatment  with  acids,  in  order 
to  impart  to  them  a  beautiful  color;  hence  the  treatment  with 
sulphuric  acid  is  generally  termed  preparatory  pickling.  As  the 
actual  pickle,  either  nitric  acid  by  itself  is  used  or  a  mixture  of  2 
parts  of  nitric  acid  and  1  of  sulphuric  acid.  Pickles  containing 
nitric  acid  possess  the  property  of  dissolving  zinc  from  the  brass 
more  quickly  than  copper,  the  surface  of  the  sheet  acquiring  in  conse¬ 
quence  of  it  a  warmer  tone,  shading  more  or  less  into  reddish.  By 
exercising  great  care,  dilute  nitric  acid  by  itself  may  be  used  as  a 
pickle,  but  the  sheets  must  be  immediately  washed,  since,  if  only 
the  slightest  trace  of  the  acid  remains,  they  acquire  after  some 
time  a  greenish  color,  due  to  the  formation  of  a  basic  cupric 
nitrate. 

It  has  been  observed  that  nitric  acid  containing  a  certain  quan¬ 
tity  of  nitrous  acid  yields  especially  beautiful  tones  of  color.  To 
obtain  them  a  small  quantity  of  organic  substance  is  added  to  the 
nitric  acid  or  to  the  mixture  of  nitric  and  sulphuric  acids.  The 
most  curious  substances  are  used  for  the  purpose,  snuff,  for  instance, 
being  highly  recommended  as  especially  efficacious  in  producing 
beautiful  colors.  The  use  of  such  substances  is,  however,  entirely 
superfluous,  there  being  a  number  of  cheaper  organic  substances 
which,  when  brought  together  with  concentrated  nitric  acid,  evolve 
nitrous  acid.  The  cheapest  of  these  materials  is  dry  saw-dust,  the 
nitric  acid  acquiring  a  short  time  after  its  introduction  an  orange- 
yellow  color,  which  is  due  to  the  products  of  decomposition  of  the 


252 


THE  METAL  WORKER’S  HANDY-BOOK. 


nitric  acid,  prominent  among  which  is  nitrous  acid.  After  taking 
the  sheets  from  the  pickle  they  are  washed,  best  in  running  water, 
in  order  to  remove  the  last  traces  of  acid.  By  quick  pickling  the 
articles  are  obtained  bright  by  the  removal  of  the  layer  of  oxide 
from  the  smooth  surface  of  the  metal.  But  sometimes  a  dull  lustre¬ 
less  surface  is  to  be  imparted  to  the  brass,  which  is  effected  by  treat¬ 
ing  the  articles  with  a  boiling  pickling  fluid  composed  also  of  nitric 
and  sulphuric  acids.  In  many  factories  this  pickle  is  prepared  by 
dissolving  i  part  of  zinc  in  3  of  nitric  acid  and  mixing  the  solu¬ 
tion  with  8  parts  each  of  nitric  and  sulphuric  acids.  The  solution 
is  heated  in  a  porcelain  dish,  and  the  articles  to  be  pickled  dipped 
in  it  30  to  40  seconds.  In  dipping  brass  articles  large  masses  of 
red-brown  vapors,  originating  from  the  products  of  decomposition 
of  the  nitric  acid,  are  evolved,  which  strongly  attack  the  lungs. 
The  operation  should,  therefore,  be  executed  under  a  well-drawing 
chimney  or,  still  better,  in  an  open  space. 

The  pickled  articles  have  a  gray  color,  and  in  order  to  bring 
out  the  pure  yellow  color  are  immersed  for  a  few  seconds  in  pure 
nitric  acid.  They  are  then  drawn  through  a  weak  solution  of  soda 
or  potash  and  finally  washed.  The  bright  metal  losing  its  beauti¬ 
ful  color  on  exposure  to  the  air  in  consequence  of  oxidation,  the 
articles  after  drying  must  be  coated  with  a  good  varnish. 

The  English  Process  of  Pickling  Brass  is  as  follows :  The  articles 
to  be  pickled  are  heated  in  muffles  at  a  dark  red  heat  and  then 
dipped  in  dilute  sulphuric  acid  for  the  production  of  a  clean  metal¬ 
lic  surface.  After  heating  and  dipping,  the  articles  are  thrown  into 
a  trough  filled  with  weak  and  impure  nitric  acid.  The  trough  is 
of  wood,  lined  with  lead  plates  and,  for  filling  it,  nitric  acid  pre¬ 
viously  employed  for  stronger  baths  is  used.  When  the  articles  are 
pure  and  of  a  uniform  color  they  are  removed  from  the  bath, 
rinsed  in  water  and  dried  in  saw-dust.  They  are  then  deadened. 
This  is  effected  by  bringing  them  into  a  bath  of  nitric  acid  diluted 
with  about  ^  water.  The  immersed  articles  become  coated  with 
a  milky  scum,  which  after  1  or  2  minutes  disappears.  When  thor¬ 
oughly  uniform,  which  is  absolutely  necessary,  the  articles  are 
dipped  in  strong  nitric  acid  and  then  instantly  immersed  in  various 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


253 


baths  of  water  to  remove  all  traces  of  acid.  If  the  article  has  de¬ 
pressions  which  might  retain  acid  it  is  necessary  to  dip  it  quickly 
into  warm  potash  solution.  The  washed  articles  are  then  allowed 
to  lie  in  clean  water  to  which  some  crude  pulverized  tartar  has  been 
added.  By  this  treatment  they  acquire  the  beautiful  dead  color  so 
highly  valued  in  commerce.  If  the  articles  are  to  be  pickled  so  as 
to  show  lustre  they  are  immediately  placed,  after  cleaning,  in  strong 
nitric  acid,  and  if  the  highest  degree  of  lustre  is  desired,  the  entire 
surface  is  thoroughly  scratch-brushed.  Polishing  is  effected  with 
finely  polished  steel  tools;  the  articles  to  be  polished  are  brushed 
over  with  ox-gall,  and  during  polishing  are  from  time  to  time 
dipped  in  water  containing  tartar.  Finally  they  are  dried  in  San¬ 
ders  wood  shavings  in  an  iron  pan  over  a  heated  hearth.  They 
are  lacquered  with  cold  shellac  solution,  which  may  be  colored  by 
an  addition  of  dragon’s  blood,  alkanet,  etc. 

The  Method  Usually  Pursued  in  the  United  States  for  Cleaning 
Brass  Parts  is  as  follows :  Prepare  a  mixture  of  i  part  of  ordinary 
nitric  acid  and  i  part  of  sulphuric  acid  in  an  earthen  vessel  and 
have  at  the  same  time  in  readiness  a  bucket  of  fresh  water  and  a 
box  of  saw-dust.  The  brass  parts  are  first  dipped  quickly  into  the 
acid,  then  into  the  water  and  finally  dried  in  the  saw-dust,  by  which 
the  brass  acquires  an  excellent  lustrous  color.  Dirty  parts  are  first 
washed  in  a  warm,  strong  solution  of  potash  and  soda. 

Articles  of  German  silver  are  pickled  by  first  immersing  them  in 
a  mixture  of  i  part  of  nitric  acid  and  12  of  water,  then  quickly  in 
a  mixture  of  equal  parts  of  nitric  acid  and  sulphuric  acid,  next 
rinsing  in  water  and  finally  drying  in  pine  saw-dust.  The  great¬ 
est  care  must,  of  course,  be  used  in  pickling,  it  being  especially 
necessary  to  see  that  the  acid  used  is  not  too  strong  and  that  the 
articles  are  not  allowed  to  remain  too  long  in  the  bath,  as  in  both 
cases  great  loss  is  incurred  by  some  of  the  metal  being  dissolved. 
To  prevent  rusting  of  the  articles  repeated  washing  with  clean 
water  and  careful  drying  are  also  absolutely  necessary. 

To  Pickle  Zinc. — Zinc  is  generally  mechanically  pickled  by 
scouring  with  sand  and  powdered  pumice.  The  bath  used  for 
brass  is  also  very  effectual.  To  larger  articles  which  cannot  well  be 


254 


THE  METAL  WORKER’S  HANDY-BOOK. 


dipped  apply  a  solution  of  potassium-ammonium  tartrate  thickened 
with  sufficient  clay  to  form  a  fluid  paste.  After  a  few  hours  rub 
the  article  with  a  brush  dipped  occasionally  into  fine  sand  moistened 
with  the  pickle. 

To  Give  a  Brilliant  Appearance  to  Tombac ,  Brass  and  Copper , 
Kaselowsky,  of  Stuttgart,  uses  the  following  process :  The  articles 
are  first  immersed  in  nitric  acid  and  then  quickly  washed  with  much 
water.  They  are  then  dipped,  with  constant  moving  to  and  fro, 
for  one  or  two  seconds  in  a  mixture,  prepared  at  least  the  evening 
before,  of  nitric  acid,  70^  ozs.  ;  sulphuric  acid,  53  ozs.  ;  hydro¬ 
chloric  acid,  2.82  ozs.  ;  alum,  5.29  ozs.  ;  sal-ammoniac,  3.17  ozs.; 
and  lampblack,  314  ozs.  When  taken  from  this  bath  the  articles 
must  be  quickly  washed  in  an  abundance  of  water.  The  bath  is  to  be 
prepared  as  follows:  First  pour  the  nitric  acid  into  the  vessel,  then 
add  the  finely  pulverized  salts,  next  the  hydrochloric  acid  and,  in 
the  course  of  1  to  2  hours,  gradually,  the  sulphuric  acid.  In  mix¬ 
ing  the  acids  considerable  heat  is  developed  and  injurious  fumes 
attacking  the  respiratory  organs  are  evolved.  It  is,  therefore,  ad¬ 
visable  to  effect  the  mixture  in  the  open  air  or  under  a  well-drawing 
chimney  and  to  use  a  large  vessel,  as  otherwise,  when  adding  the 
sulphuric  acid,  the  fluid  might  run  over.  This  acid  mixture  has 
the  advantage  that  it  can  be  used  for  a  long  time,  it  only  being 
necessary  to  add  some  sulphuric  acid  and  later  on  some  nitric  acid 
and  sal-ammoniac.  The  objects  are  but  little  attacked  by  the  acid 
mixture,  and  it  is,  therefore,  especially  adapted  for  printed  metal 
wares  and  lamp  fixtures,  to  which  it  imparts  a  gold-like  appearance. 
Copper,  especially  galvano-plastic  articles,  acquire  a  much  brighter 
and  more  lustrous  appearance  by  it. 

To  Polish  Metals. — All  polishing  of  metals  is  begun,  in  the  first 
instance,  by  rubbing  down  the  surface  by  some  hard  substance  that 
will  produce  a  number  of  scratches  in  all  directions,  the  level  of 
which  is  nearly  the  same  and  which  obliterate  the  marks  of  the  file, 
scraper  or  turning  tool  that  has  been  first  employed.  For  this 
purpose  coarse  emery  is  used,  or  pumice  and  water,  or  sand  and 
water  applied  upon  a  piece  of  soft  wood,  or  of  felt,  skin  or  similar 
material.  When  the  first  coarse  marks  have  thus  been  removed, 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


255 


next  proceed  to  remove  the  marks  left  by  the  first  polishing 
material  by  finely-powdered  pumice  stone  ground  up  with  olive 
oil,  or  by  finer  emery  and  oil.  In  some  cases  certain  polishing 
stones  are  employed,  for  instance,  a  kind  of  hard  slate  used  with 
water.  To  proceed  with  the  polishing  still  finer  powders  are  used, 
such  as  tripoli  and  rotten  stone.  Putty  of  tin  and  crocus  martis 
are  also  used  for  higher  degrees  of  polish.  But  the  whole  process 
consists  merely  in  removing  coarse  scratches  by  substituting  those 
which  are  finer  and  finer  until  they  are  no  longer  visible  to  the 
naked  eye ;  and  even  long  after  that,  if  the  surface  is  examined 
by  a  microscope,  it  will  be  seen  that  what  appeared  without  any 
scratches  is  covered  all  over  with  an  infinity  of  them,  but  so  minute 
that  they  require  a  high  magnifier  to  be  discovered.  It  is  evident 
that  great  care  must  be  taken  to  have  the  last  polishing  material 
uniformly  fine,  for  a  single  grain  or  two  of  any  coarse  substance 
mixed  with  it  will  produce  visible  scratches  instead  of  a  perfectly 
polished  surface. 

Polishing  by  Means  of  Wheels. — To  give  metallic  articles  the 
highest  degree  of  lustre,  bodies  are  used  which,  though  they  attack 
the  articles  very  delicately,  possess  sufficient  hardness  to  remove 
the  scratches  and  roughness  produced  by  grinding  with  emery, 
pumice,  etc.  These  agents  are  called  “polishing  agents”  or,  as 
they  are  always  used  in  a  pulverulent  form,  “  polishing  powders,” 
the  most  important  of  them  being  lime,  ferric  oxide,  tripoli,  tin- 
putty,  chalk  and  graphite. 

Lime  is  used  in  a  burned,  unslaked  state.  It  should  be  free 
from  all  admixtures,  and  especially  from  carbonic  acid  and  water. 
An  excellent  variety  is  the  so-called  “Vienna  lime.”  It  is  pre¬ 
pared  from  a  variety  of  dolomite  which  is  first  burned,  then  slaked 
and  finally  glowed  for  a  few  hours.  This  polishing  agent  consists 
of  lime  and  magnesia,  and  should  be  kept  in  well-closed  cans,  as 
otherwise  it  absorbs  carbonic  acid  and  moisture  from  the  air  and 
becomes  useless.  In  using  Vienna  lime  the  articles  to  be  polished 
are  brushed  over  either  with  spirits  of  wine  or  oil. 

Ferric  Oxide  is  used  in  its  natural  state,  and  is  also  prepared  arti¬ 
ficially.  The  natural  ferric  oxide,  such  as  hematite,  specular  and 


256 


THE  METAL  WORKER’S  HANDY-BOOK. 


red  iron  ores,  should  be  ground  fine  and  elutriated.  The  polish¬ 
ing  agent  known  as  caput  mortuum ,  crocus,  colcothar,  jewellers'  red 
or  rouge,  obtained  by  heating  ferrous  or  ferric  sulphate  in  the 
preparation  of  fuming  sulphuric  acid,  is  also  ferric  oxide.  Both 
these  oxides  are  very  useful  polishing  agents.  For  polishing  fine 
articles  of  steel,  gold,  gilt,  bronze,  etc.,  the  jewellers’  red  is  pre¬ 
pared  artificially.  For  this  purpose  mix  pulverized  green  vitriol 
with  pulverized  saltpetre  and  common  salt,  stir  the  mixture  with 
water  to  a  thin  paste  and  boil  down  the  mass  in  an  iron  crucible  to 
dryness.  The  mixture  thus  obtained  is  heated  in  a  Hessian  cru¬ 
cible  at  a  red  heat  until  it  becomes  quiet  and  homogeneous;  it  is 
then  poured  out,  and  when  cool,  powdered,  boiled  with  water  and 
washed.  It  is  advisable  to  somewhat  elutriate  the  powder  thus 
obtained  to  eliminate  grains  of  sand  which  may  have  reached  it  from 
the  crucible.  The  powder  is  finally  collected  upon  a  cloth  and 
dried.  For  50  parts  of  crystallized  green  vitriol  25  parts  of  pure 
nitrate  of  soda,  13  of  common  salt  and  18  of  sodium  sulphate  may 
be  used.  A  larger  addition  of  saltpetre  gives  a  preparation  of  a 
redder  color,  and  an  increase  of  potassium  sulphate  and  a  higher 
temperature  one  of  a  more  violet  color.  An  increase  of  common 
salt  produces  a  browner  color,  and  the  jeweller’s  red  is  obtained 
in  lustrous  lamina;  the  violet  powder  is  harder  than  the  red.  The 
former  (steel  rouge)  is,  therefore,  chiefly  used  for  steel,  and  the 
latter  (gold  rouge)  for  gold  and  silver. 

According  to  another  method,  1  part  of  soda  is  dissolved  in  4 
of  water  and  the  solution  heated  to  boiling.  Add  gradually  to  the 
boiling  fluid  somewhat  more  than  part  of  green  vitriol  and  con  ¬ 
tinue  boiling  for  some  time.  When  cold  a  greenish-white  mass  of 
ferrous  carbonate  is  found  on  the  bottom  of  the  vessel.  Pour  off 
the  supernatant  fluid,  wash  the  precipitate  with  much  water,  then 
dry  it  and  finally  convert  it  by  slight  glowing  in  a  clay  crucible 
into  red  ferric  oxide.  In  using  this  jewellers’  rouge  the  articles 
are  generally  moistened  with  spirits,  though  sometimes  simply  with 
water. 

Tripoli  is  generally  a  gray-white  or  yellow  powder  of  slight  hard¬ 
ness,  and  consists  almost  wholly  of  the  cast  shells  of  microscopic 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


257 


organisms.  It  serves  chiefly  for  polishing  soft  metals,  and  is  used 
first  with  oil  and  lastly  dry. 

Tin-putty  is  artificially  prepared  by  glowing  oxalate  of  tin,  which 
is  obtained  by  decomposing  tin-salt  with  oxalic  acid. 

Chalk  is  only  used  in  the  form  of  whiting. 

To  prevent  scattering,  the  polishing  agents  are  generally  mixed 
with  a  fluid,  water,  spirit  of  wine  or  oil  being  used  for  the  purpose. 
With  these  fluids  the  polishing  agents  are  made  into  a  paste  and  a 
thin  layer  of  it  applied  to  the  polishing  tool.  For  the  latter  a 
piece  of  leather  or  cloth  frequently  suffices.  It  is  provided  with 
the  polishing  agent,  pressed  by  the  hand  upon  the  article  to  be 
polished  and  moved  to  and  fro  upon  it.  Smooth  articles  which 
can  be  secured  in  the  lathe  are  polished  by  pressing  the  tool  pro¬ 
vided  with  the  polishing  agent  against  the  revolving  article.  In  this 
case  the  flexible  pieces  of  leather  or  cloth  can  be  replaced  by  sticks 
of  wood  covered  with  leather  or  cloth.  These  tools  are  called 
“polishing  files.”  By  joining  two  of  them  together  by  a  hinge- 
joint  the  “  polishing  stock  ”  is  formed,  which  is  used  for  polishing 
smooth  bodies  in  the  lathe. 

Since  in  polishing,  as  well  as  in  grinding,  it  is  absolutely  neces¬ 
sary  that  either  the  work  or  the  tool  move  with  great  velocity, 
disk-like  tools  are  generally  used,  which  are  secured  either  in  a 
lathe  or  a  lathe-like  machine,  which  allows  of  a  still  more  rapid 
revolution  of  the  disks  than  the  lathe.  These  disks  are  known  as 
buff-wheels,  one  variety  of  them  consisting  of  a  wooden  disk 
covered  with  walrus  leather. 

The  last  or  dead  grinding  is  also  executed  with  such  polishing 
disks.  For  this  purpose  very  finely  elutriated  emery  is  uniformly 
applied  to  the  leather  of  the  polishing  wheel.  When  dry  a  second 
and  third  application  of  emery  may,  if  necessary,  be  made.  This 
disk  is  called  “roughing  wheel;”  when  somewhat  worn  it  is 
termed  “medium  wheel,”  and  when  almost  completely  denuded 
of  grinding  agent  “fine  wheel.”  In  grinding  with  these  wheels, 
oil  is  used.  When  the  grinding  agent  is  used  up  the  remainder  is 
soaked  with  warm  water  and  scraped  off  with  a  knife  to  prepare 
the  disk  for  a  fresh  application.  In  consequence  of  the  rapid 
17 


258 


THE  METAL  WORKER’S  HANDY-BOOK. 


rotation  of  the  disk  the  leather  and  the  layer  of  emery  become 
brittle  and  full  of  fissures.  To  remove  this  defect  a  piece  of  tallow 
is  held  against  the  revolving  disk,  and  it  is  then  smoothed  by  press¬ 
ing  a  smooth  stone  against  it.  For  polishing,  the  polishing  agent 
mixed  with  oil  is  applied  to  the  clean  leather  of  the  disk. 

Another  kind  of  buffing  wheel  is  made  by  solidly  pressing  old 
or  new  woollen  rags  between  two  iron  disks  provided  with  holes 
and  pins.  The  wheels  are  secured  to  the  spindle  of  the  polishing 
machine  and  first  made  round,  which  is  readily  effected  by  holding 
the  sharp  edge  of  a  scythe  against  the  revolving  cloth  disk.  In 
using  the  cloth-wheel  Vienna  lime  mixed  with  oil  is  first  employed 
and  finally  dry  Vienna  lime. 

If  a  large  number  of  small  articles,  such  as  buckles,  steel  beads, 
metal  buttons,  steel  watch  chains,  ferules,  etc.,  are  to  be  polished  at 
one  time,  a  tumbling  drum  or  box  is  used.  In  its  simplest  form 
the  apparatus  consists  of  a  barrel  of  suitable  size,  through  the  head 
and  bottom  of  which  passes  a  square  axle  of  hard  wood.  This  axle 
rests  with  a  pivot  of  round  iron  in  a  suitable  frame,  and  is  pro¬ 
vided  either  with  a  crank  or  a  pulley. 

The  manipulation  of  the  apparatus  varies  according  to  the  con¬ 
dition  of  the  articles  to  be  polished.  Generally  scales  and  other 
traces  of  previous  working  have  to  be  removed.  For  this  purpose 
the  drum  is  filled  one-quarter  full  with  river  sand,  and  after  moist¬ 
ening  it  with  an  equal  volume  of  dilute  sulphuric  acid,  as  many 
of  the  articles  to  be  polished  are  thrown  upon  the  moist  layer  of 
sand  that  somewhat  more  than  a  quarter  of  the  barrel-space  re¬ 
mains  empty.  The  aperture  for  filling  is  then  closed  and  the 
drum  revolved,  the  contents  being  from  time  to  time  examined  to 
see  whether  they  are  sufficiently  scoured.  To  accelerate  the  scour¬ 
ing  action  of  the  sand  it  is  advisable  to  provide  the  drum  inside 
with  a  few  rounded-off  wooden  pieces,  so  that  the  articles  placed 
in  it  strike  each  other  and  are  thoroughly  shaken  up,  or  the  drum 
itself  may  be  of  a  hexagonal  shape. 

After  tumbling  with  sand  for  i  to  2  hours,  the  articles  are  brought 
into  a  drum  partially  filled  with  leather-waste,  charcoal,  emery  and 
oil.  When  actually  ground  in  this  drum  they  are  polished  or  made 


CLEANSING,  GKINDING,  PICKLING,  POLISHING. 


259 


lustrous  in  a  third  drum  partially  filled  with  Vienna  lime  to  which, 
for  cheapness  sake,  pulverized  charcoal  and  coarse  beech  saw-dust 
may  be  added. 

A  very  practical  form  of  tumbling  drum,  in  which  a  change  of 
position  of  the  contents  must  constantly  take  place,  is  shown  in 
Fig.  8.  The  drum  A,  of  wood  or  iron,  is  obliquely  placed  upon 
the  shaft  B.  The  objects  are  introduced  into  the  drum  through 
the  door  C.  The  drum  is  revolved  by  a  crank,  or  by  a  belt  by 
means  of  the  pulley  D.  All  portions  of  the  drum  describe  thereby 


ellipses,  the  walls  of  the  drum  being  now  raised  (indicated  by  the 
dotted  lines)  and  then  lowered,  so  that  the  articles  in  the  drum  are 
in  constant  motion  and  rub  against  each  other. 

According  to  another  method,  small  articles  of  iron  are  first 
pickled  with  acid,  then  washed  with  boiling  water,  next  scoured 
bright  in  a  drum  with  steel  powder  or  powdered  cast-iron,  and 
finally  polished  in  a  mixture  of  hard  wood  saw-dust,  elutriated 
tripoli,  and,  according  to  circumstances,  jewellers’  rouge. 

Polishing  with  the  Burnisher  or  Burnishing- stone. — To  burnish 
an  article  is  to  polish  it  by  removing  the  small  roughness  upon  its  sur¬ 
face,  and  this  is  performed  by  a  burnisher.  This  mode  of  polishing 
is  the  most  expeditious  and  gives  the  greatest  lustre  to  a  polished 
body.  It  removes  the  marks  left  by  the  emery,  tin-putty  or  other 
polishing  agents,  and  gives  to  the  burnished  articles  a  black  lustre 
resembling  that  of  looking-glass.  The  form  and  construction  of 
the  burnisher  is  extremely  variable,  according  to  the  respective 
trades,  and  it  must  be  adapted  to  the  various  kinds  of  work  in  the 


260 


THE  METAL  WORKER’S  HANDY-BOOK. 


same  art.  In  general,  as  this  tool  is  only  intended  to  efface  in¬ 
equalities,  whatever  substance  the  burnisher  is  made  of  is  of  little 
consequence  to  the  article  burnished,  provided  only  that  it  is  of  a 
harder  substance  than  that  article. 

The  burnishers  used  are  of  two  kinds,  of  steel  and  of  hard  stone 
They  are  either  curved  or  straight,  rounded  or  pointed,  and  made 
so  as  to  suit  the  projecting  parts  or  the  hollows  of  the  piece.  Steel 
burnishers  are  made  of  the  finest  quality  of  steel,  filed  into  a  suit¬ 
able  shape,  hardened  and  ground,  and  finally  polished  with  Vienna 
lime  or  jewellers’  rouge.  Stone  burnishers  are  made  of  jasper  as 
well  as  of  agate,  but  red  hematite,  known  under  the  name  of  blood¬ 
stone,  is  most  frequently  used  for  the  purpose.  This  raw  material 
is  found  only  in  few  places,  and  among  several  hundred  weight  of 
it  are  frequently  found  only  a  few  pounds  of  suitable  stones,  which 
generally  occur  as  kernels  enclosed  in  larger  pieces.  To  these 
pieces  an  approximate  shape  is  given  by  skillful  splitting.  They 
are  then  rounded  either  with  the  grindstone,  or  rubbed,  so  that 
they  present,  at  the  bottom,  a  very  blunt  edge,  or  sometimes  a 
rounded  surface.  These  are  polished  with  emery,  like  steel  bur¬ 
nishers,  and  are  finished  by  being  rubbed  upon  a  leather  covered 
with  jewellers’  rouge  or  Vienna  lime.  Blood-stone  is  harder  than 
case-hardened  steel,  the  cross-grain  of  the  fibrous  pieces  especially 
excelling  in  great  hardness. 

Fig.  9  shows  the  most  common  forms  of  burnishing  tools. 
Both  must  be  perfectly  free  from  small  fissures  and  possess  the 
highest  polish.  The  burnisher  is  mounted  in  a  wooden  handle, 
and  firmly  fixed  by  a  copper  ferule.  The  operation  of  burnishing 
is  very  simple.  Take  hold  of  the  tool  very  near  to  the  stone,  and 
lean  very  hard  with  it  on  those  parts  which'  are  to  be  burnished, 
causing  it  to  glide  by  a  backward  and  forward  movement  without 
taking  it  off  tire  piece.  When  it  is  requisite  that  the  hand  should 
pass  over  a  large  surface  at  once,  without  losing  its  point  of  sup¬ 
port  on  the  work-bench,  in  taking  hold  of  the  burnisher  be  careful 
to  place  it  just  underneath  the  little  finger.  By  these  means  the  work 
is  done  more  quickly,  and  the  tool  is  more  solidly  fixed  in  the  hand. 
During  the  whole  process  the  tool  must  be  continually  moistened 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


261 


with  black  soap-suds.  The  water  with  which  it  is  frequently  wetted 
causes  it  to  glide  more  easily  over  the  work,  prevents  it  from  heat¬ 
ing  and  facilitates  its  action.  The  black  soap  containing  more 
alkali  than  the  common  soap,  acts  with  greater  strength  in  cleansing 
off  any  greasiness  which  might  still  remain  on  the  surface ;  it  also 
more  readily  removes  the  spots  which  would  spoil  the  beauty  of  the 
burnishing.  In  consequence  of  the  friction  the  burnisher  soon 
loses  its  bite  and  slips  over  the  surface  as  if  it  were  oily.  In  order 
to  restore  its  action  it  must  from  time  to  time  be  rubbed  on  the 
leather.  The  leather  is  fixed  on  a  piece  of  hard  wood  with  shallow 


8^5 


4  6 


Fig.  9. 


furrows  along  it.  There  are  generally  two  leathers — one  made  of 
sole  leather,  and  the  other  of  buff  leather.  The  first  is  impregnated 
with  a  little  oil  and  jewellers’  rouge,  and  is  particularly  used  for 
the  blood-stone  burnishers,  the  other  has  only  a  little  tin-putty 
scattered  in  the  furrows,  and  is  intended  exclusively  for  rubbing 
steel  burnishers,  as  they  are  not  so  hard  as  the  blood-stones.  Blood¬ 
stone  being  very  hard,  the  workman  uses  it  whenever  he  can  in 
preference  to  the  steel  burnisher.  It  is  only  on  small  articles  and 
in  difficult  places  that  steel  burnishers  are  used,  as  they  by  their 
variety  of  form  are  adapted  to  all  kinds  of  work.  In  general,  the 


262 


THE  METAL  WORKER’S  HANDY-BOOK. 


blood-stone  greatly  reduces  the  labor.  When  the  articles,  on  ac¬ 
count  of  their  minuteness,  cannot  be  conveniently  held  in  the 
hand,  they  are  fixed  in  a  satisfactory  frame  on  the  bench,  but  under 
all  circumstances  be  very  careful  to  manage  the  burnisher  so  as  to 
leave  untouched  those  parts  of  the  work  which  are  intended  to  re¬ 
main  dull.  When  in  burnishing  an  article,  which  is  plated  or  lined 
with  silver,  there  is  any  place  where  the  layer  of  precious  metal  is 
removed,  restore  it  by  silvering  these  places.  The  burnishing 
being  finished  remove  the  soap-suds  which  still  adhere  to  the  sur¬ 
face  of  the  work  by  rubbing  with  a  piece  of  old  linen  cloth.  But 
when  there  are  a  great  number  of  small  pieces  to  be  finished,  to 
throw  them  into  soap-suds  and  dry  them  afterwards  in  saw-dust  is 
more  expeditious.  The  burnishing  of  gold-leaf  or  silver  on  wood 
is  performed  with  burnishers  made  of  wolves’  or  dogs’  teeth,  or 
agates  mounted  in  iron  or  wooden  handles.  When  about  to 
burnish  gold  applied  on  other  metals,  dip  the  blood-stone  burnisher 
into  vinegar;  this  kind  being  exclusively  used  for  that  purpose. 
But  when  burnishing  leaf-gold  on  prepared  surfaces  of  wood,  keep 
the  stone,  or  tooth,  perfectly  dry.  The  ordinary  engraver’s  bur¬ 
nisher  is  a  blade  of  steel,  made  thin  at  one  end,  to  fit  into  a  small 
handle  to  hold  it  by.  The  part  in  the  middle  of  the  blade  is 
rounded  on  the  convex  side,  and  is  also  a  little  curved.  The 
rounded  part  must  be  well  polished  and  the  tool  be  very  hard. 
This  burnisher  is  used  to  give  the  last  polish  to  such  parts  of  cop¬ 
per  and  steel  plates  as  may  have  been  accidentally  scratched,  or 
speckled,  where  false  lines  are  to  be  removed,  and  also  to  lighten 
in  a  small  degree  such  parts  as  have  been  too  deeply  etched  or 
graved.  In  clock-making,  those  pieces  or  parts  are  burnished 
which,  on  account  of  their  size  or  form,  cannot  be  conveniently 
polished.  The  burnishers  are  of  various  forms  and  sizes:  they  are 
all  made  of  cast-steel,  very  hard  and  well  polished ;  some  are 
formed  like  sage-leaf  files,  others  like  common  files — the  first  are 
used  to  burnish  screws  and  pieces  of  brass,  the  others  are  used  for 
flat  pieces.  The  clock-makers  have  also  very  small  ones  of  this 
kind  to  burnish  their  pivots,  which  are  called  pivot  burnishers. 

Burnishing  Cutlery. — The  burnishing  of  cutlery  is  executed  by 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


263 


hand  or  vice  burnishers ;  they  are  all  made  of  fine  steel,  hardened 
and  well  polished.  The  first  kind  have  nothing  particular  in  their 
construction ;  but  vice  burnishers  are  formed  and  mounted  in  a 
very  different  manner.  On  a  long  piece  of  wood,  placed  horizon¬ 
tally  in  the  vice,  is  fixed  another  piece,  as  long,  but  bent  in  the 
form  of  a  bow,  the  concavity  of  which  is  turned  downwards. 
These  two  pieces  are  united  at  one  of  their  extremities  by  a  pin 
and  hook,  which  allows  the  upper  piece  to  move  freely  around  this 
point  as  a  centre.  The  burnisher  is  fixed  in  the  middle  of  this 
bent  piece,  and  it  is  made  more  or  less  projecting  by  the  greater  or 
lesser  length  which  is  given  to  its  base.  The  movable  piece  of 
wood,  at  the  extremity  opposite  to  the  hook,  is  furnished  with  a 
handle,  which  serves  the  workman  as  a  lever.  This  position  allows 
the  burnisher  to  rest  with  greater  force  against  the  article  to  be 
burnished,  which  is  placed  on  the  fixed  piece  of  wood.  The 
burnisher  has  either  the  form  of  the  face  of  a  round-headed  ham¬ 
mer,  well  polished  to  burnish  those  pieces  which  are  plain  or  con¬ 
vex,  or  the  form  of  two  cones  opposed  at  their  summits,  with  their 
bases  rounded,  to  burnish  those  pieces  which  are  concave  or  ring- 
shaped. 

To  Burnish  Silver. — Commence  by  cleaning  off  any  kind  of  dirt 
which  the  surfaces  of  the  silver  articles  had  contracted  whilst  being 
made,  as  that  would  entirely  spoil  the  burnishing.  For  this  pur¬ 
pose  take  pumice-stone  powder,  and  with  a  brush  made  very  wet 
in  strong  soap-suds  rub  the  various  parts  of  the  work,  even  those 
which  are  to  remain  dull,  which,  nevertheless,  receive  thus  a  beauti¬ 
ful  white  appearance ;  wipe  with  an  old  linen  cloth  and  proceed  to 
the  burnishing. 

Scratch-brushing, — For  brightening  articles  in  relief,  steel  or 
stone  burnishers  can  be  but  seldom  employed,  scratch-brushes  being 
used  in  this  case.  The  shape  of  the  scratch-brush  varies  with  the 
articles  to  be  operated  upon.  A  hand  scratch-brush  is  made  of 
numerous  wires  of  hardened  brass  selected  from  a  bundle  of  or  coil 
of  large  diameter,  so  that  the  wires  have  little  tendency  when  in 
place  to  curve.  To  make  a  good  hand  scratch-brush,  proceed  as 
follows:  Select  a  coil  of  brass  wire  of  the  proper  degree  of  fineness 


264 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


(Fig.  io),  and  bind  it  tightly  with  strong  twine  for  about  two-thirds 
of  the  intended  length  of  the  brush — 6  or  8  inches — (Fig.  ii). 
Then,  with  a  chisel,  cut  the  bundle  of  wire  close  to  the  cord  at  one 
end,  and  about  2  inches  from  it  at  the  other  end.  Then  dip  the 
close-cut  end  into  a  neutral  solution  of  chloride  of  zinc,  and  plunge 
it  into  molten  tin,  which  solders  all  the  wires  and  prevents  their 
separation,  and  injury  to  the  hand  of  the  operator.  The  tool  thus 
made  may  be  used  as  it  is,  but  it  is  preferable  to  fix  it  by  means  of 
another  string  to  a  thin  wooden  handle,  which  projects  above  the 
soldered  end  (Fig.  12).  Scratch -brushes  are  also  made  by  cutting 
a  coil  of  wire  for  a  length  of  from  12  to  16  inches,  binding  it  in 


the  middle,  and  doubling  it  so  as  to  unite  the  two  ends  (Fig.  13). 
This  process  is  less  economical,  and  the  wires  have  a  tendency  to 
become  entangled.  Very  small  scratch-brushes  are  necessary  for 
reaching  sinuosities  and  depressions  in  the  work,  and  other  parts 
difficult  of  access.  An  old  scratch-brush,  the  wires  of  which  have 


CLEANSING,  GKINDING,  PICKLING,  POLISHING. 


265 


been  bent  in  every  direction,  when  fixed  to  a  long  handle,  is  useful 


for  scouring  the  interior  of  certain  pieces,  such  as  Etrus¬ 
can  vases,  coffee-urns,  etc.  (Fig.  14).  The  varnishers  on 
metal  use  for  rapid  work  a  kind  of  brush  (Figs.  15  and 
16),  with  long  and  stiff  brass  wires.  Such  brushes  are 
only  used  for  the  preparation  of  articles  of  considerable 
size,  such  as  clock  dials,  hearth  furniture,  and  the 


Fig.  14. 


Fig.  16. 


Fig.  i5' 


Scratch-brushing  is  seldom  done  dry;  the  tool  as  well  as  the 
pieces  must  be  constantly  wet  with  fluids,  especially  such  as  produce 
a  foam  in  brushing,  for  instance,  water  and  vinegar,  or  sour  wine, 
or  solutions  of  cream  of  tartar  or  alum,  when  it  is  desired  to 
brighten  a  gold  deposit  which  is  too  dark ;  but  that  most  generally 
used  is  a  decoction  of  licorice-root,  of  horse-chestnut,  of  marsh¬ 
mallow,  of  soap-wort,  or  of  the  bark  of  Panama-wood,  all  of  which 
being  slightly  mucilaginous,  allow  of  a  gentle  scouring  with  the 
scratch-brush,  with  the  production  of  an  abundant  froth.  A  good 
adjunct  for  scratch-brushing  is  a  shallow  wooden  tub  containing  the 
solution  employed,  with  a  board  laid  across  it,  nearly  level  with  the 
edges,  which,  however,  project  a  little  above.  This  board  serves 
as  a  rest  for  the  pieces. 

With  small  objects  and  articles  of  jewelry,  the  operator  holds  the 
scratch-brush  as  he  would  a  writing-pen,  and  moves  it  over  the 
article  with  a  back-and- forward  motion  imparted  by  the  wrist  only, 
the  forearm  resting  on  the  edge  of  the  tub.  For  larger  articles,  on 
the  contrary,  the  operator  holds  his  extended  fingers  close  to  the 
lower  part  of  the  scratch-brush,  so  as  to  give  the  wires  a  certain 
support,  and,  with  raised  elbow,  strikes  the  piece  repeatedly,  at 
the  same  time  giving  the  tool  a  sliding  motion.  When  a  hollow  is 


266 


TITE  METAL  WORKER’S  HANDY-BOOK, 


met  with  which  cannot  be  scoured  longitudinally,  a  twisting  motion 
is  imparted  to  the  tool. 

Circular  scratch-brushes  in  which  the  wires  are  arranged  radially 
are  used  for  scouring  articles  that  admit  of  their  use,  such  as  table 
ware  and  plated  wares  in  general.  These  circular  scratch-brushes 


are  attached  to  the  spindle  of  a  lathe,  and  the  wires  consequently 
all  receive  a  uniform  motion  in  the  same  direction.  The  scratch¬ 
brush  lathe  shown  in  Fig.  17  consists  of  a  circular  brush  of  brass 
wires,  with  a  metal  or  wooden  case,  mounted  upon  a  spindle  run¬ 
ning  in  two  bearings,  and  driven  either  by  foot  or  by  steam-power. 
The  wires  are  from  2  to  3  inches  long,  and  the  form  of  the  bmsh 


CLEANSING,  GRINDING,  PICKLING,  POLTSHfNG. 


267 


is  shown  in  Fig.  18.  The  top  of  the  brush  revolves  towards  the 
operator,  who  presents  the  object  to  be  scratched  to  the  bottom. 
The  brush  is  surrounded  by  a  wooden  cage  or  screen  to  prevent 
splashing.  It  is  open  in  front,  and  above  it  is  placed  a  reservoir 
of  one  of  the  liquids  above  named,  from  which  a  slender  jet  of  the 
liquid  is  allowed  to  dribble  upon  the  top  of  the  brush.  In  order 
to  protect  the  operator  against  the  water  projected  by  the  rapid 
motion,  there  is  fixed  to  the  top  of  the  frame  a  small  inclined 
board,  which  reaches  a  little  lower  than  the  axis  of  the  brush,  with¬ 
out  touching  it.  This  board  receives  the  projected  liquid  and  lets 
it  fall  into  a  zinc  trough  which  forms  the  bottom  of  the  box. 


Fig.  ,8. 


Through  an  outlet  provided  in  one  of  the  angles  of  the  trough  a 
gum  tube  conveys  the  waste  liquid  to  a  reservoir  below. 

The  above-described  hand  and  lathe  scratch-brushes  are  made  of 
wire  of  various  gauges,  from  coarse  to  very  fine,  according  to  their 
intended  uses.  Scratch-brushes  of  spun  glass,  with  fibres  of  extreme 
fineness  and  elasticity,  are  also  used  for  scouring  very  delicate 
objects. 

When  a  hand  scratch-brush  becomes  too  short  the  twisted  ends 
are  cut  off  with  a  cold-chisel,  and  a  new  portion  of  wire  is  uncov¬ 
ered  by  removing  part  of  the  string  wrapping.  The  best  way  to 
remove  the  twisted-wire  ends  is  by  resting  the  scratch-brush  upon 
a  lead  block,  and  cutting  them  off  with  a  sharp  cold-chisel,  if  pos¬ 
sible  with,  one  stroke  of  the  hammer.  Scratch-brushes  must  be 
carefully  looked  after  and  their  wires  kept  in  good  order.  When 
they  begin  to  curl,  they  are  now  and  then  beaten  with  a  mallet  of 


268 


THE  METAL  WORKER’S  HANDY-BOOK. 


boxwood  upon  a  small  block  held  between  the  knees,  so  as  not  to 
produce  a  dead  stroke.  Scratch-brushes  kept  too  long  in  water 
become  hard.  If  they  become  greasy,  they  are  cleansed  in  caustic 
potash  ;  oxide  is  removed  by  acid.  Dipping  in  nitric  acid  is  some¬ 
times  resorted  to  for  diminishing  the  size  of  the  wires  and  making 
them  smoother.  The  circular  brush  is  occasionally  reversed,  in 
order  to  change  the  direction  of  the  wires. 

Polishing  of  the  Separate  Metals. — Iron  and  Steel  are  generally 
polished  after  treatment  with  emery.  For  this  purpose  tin  putty, 
Vienna  lime  or  oxide  of  iron  (steel  rouge)  are  generally  employed, 
the  polishing  material  or  the  article  being  moistened  with  water  or 
spirit.  Polishing  wheels  (buff  or  cloth  wheels)  are  best  for  the 
purpose,  though  buff  sticks  and  wooden  sticks  as  well  as  woollen 
rags  are  also  employed. 

Copper,  Brass,  German  Silver  and  Tombac  are  polished  with 
Vienna  lime  and  oil.  If  previously  pickled  the  burnisher  is 
mostly  used. 

Polishing  with  the  burnisher  is  always  executed  wet.  Gas-fix¬ 
tures  are  polished,  after  pickling,  in  the  spinning  lathe  with  the 
burnisher,  a  peculiar  fluid  (polish)  being  used,  which,  according  to 
O.  Ronicke,  is  composed  of:  orange  shellac,  dissolved  in  spirits, 
1000  parts  by  weight;  powdered  turmeric  root,  1000  ;  tartar,  2000; 
ox-gall,  50;  alcohol,  100;  and  water,  3000.  Dip  the  burnisher 
in  the  fluid  and  polish  the  article,  or  wrap  a  linen  rag  moistened 
with  the  fluid  round  a  piece  of  wood  and  hold  the  rag  with  the  left 
hand  upon  the  place  where  the  pressure  with  the  burnisher  is  ap¬ 
plied.  By  drying  the  article  with  a  linen  rag  a  polish  equal  to 
that  with  Vienna  chalk  is  obtained. 

Gold  is  polished  with  jewellers’  rouge,  which  is  mixed  with  alco¬ 
hol  and  applied  to  the  buff-stick. 

Silver  is  polished  with  the  burnisher  or  bloodstone,  soap  water, 
small  beer,  etc.,  being  used  in  connection  with  it. 

Silvered  and  Plated  Ware  are  also  polished  with  Vienna  lime. 

Dead  Lustre  on  Articles  of  Gold  and  Silver  is  produced  by  means 
of  scratch-brushes  of  finely  spun  glass  threads. 

Tin  Articles  are  ground  and  polished  with  Vienna  lime  or  whiting, 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


269 


the  first  being  used  with  linen  rags  and  the  latter  with  chamois  leather. 
If  only  places  in  relief  are  to  be  polished  a  broad,  rounded-off 
burnisher  is  used  and  as  polishing  agent  soap  water,  white  of  egg, 
ox-gall  diluted  with  water,  decoction  of  soap  root,  etc.  The  ar¬ 
ticles  are  finally  washed  with  water  containing  tartar  and  dried. 

Antimony  and  Lead  Alloys  are  polished  with  burnt  magnesia  upon 
soft  leather  or  with  fine  jewellers’  rouge. 

Zinc  is  first  scraped  and  finally  polished  with  pulverized  wood 
charcoal  or  Vienna  lime. 

The  polished  articles  are  generally  dried  in  heated  saw-dust  and, 
after  drying,  freed  from  adhering  saw-dust  with  a  cotton  rag  or 
soft  leather.  Gilded  or  silvered  articles  are  dipped  in  hot  water, 
dried  with  cotton  or  linen  cloths  and  finally  rubbed  with  soft 
leather. 

Vienna  lime  produces  a  light  polish  upon  brass,  steel,  etc.,  but 
iron  oxide  a  dark  lustre,  the  difference  in  the  coloration  being  very 
likely  due  to  some  of  the  polishing  agent  remaining  in  the  pores 
of  the  metal. 

Polishing  Agents. — Old  and’  used  metallic  objects  lose  in  the 
course  of  time  their  lustre  produced  by  polishing;  they  become 
dull  and  covered  with  a  crust  of  dust,  oxides,  sulphur  combinations, 
etc.  To  cleanse  such  objects  polishing  agents  acting  either  me¬ 
chanically  or  chemically  are  used. 

To  the  mechanically  acting  polishing  agents  belongs  the  so-called 
Paris  rouge.  It  is  used  for  restoring  lustre  to  gold  articles  by  care¬ 
fully  rubbing  them  with  leather  dipped  in  it.  Under  the  name 
Parisian  polishing  powder  a  rose-colored  powder  is  brought  into 
commerce.  It  is  especially  adapted  for  polishing  silver,  but  may 
also  be  used  for  articles  of  steel,  copper  or  gold.  It  consists  of  a 
mixture  of  6  parts  of  carbonate  of  magnesia  and  x  of  jewellers’  red. 
For  use  dip  a  rag  moistened  with  spirits  or  water  in  the  powder  and 
after  thoroughly  rubbing  the  article  dry  it  with  soft  leather. 

1  Emery-cloth  may  be  used  for  scouring,  but  it  gives  no  lustre,  be¬ 
cause  the  polishing  agent  is  sharp-grained  and  applied  to  the  cloth. 
More  suitable  is  a  polishing  agent  consisting  of  fustian  saturated 
with  a  dilute  solution  of  waterglass.  By  washing  the  impregnated 


270 


THE  METAL  WORKER'S  HANDY-BOOK. 


stuff  the  silicic  acid  and  a  portion  of  the  potash  remain  behind. 
This  polishing  cloth  is  well  adapted  for  cleansing  and  scouring 
bright  brass. 

Another  kind  of  polishing  rags  is  obtained  by  dissolving  4  parts 
by  weight  of  Castile  soap  in  20  of  water  and  adding  2  of  tripoli 
to  the  solution.  Strips  of  linen  are  then  saturated  with  the  solu¬ 
tion  and  allowed  to  dry.  According  to  another  method  polishing 
rags  are  prepared  as  follows:  Dip  flannel  rags  in  a  solution  of  20 
parts  of  dextrin  and  30  of  oxalic  acid  in  20  of  logwood  decoction, 
wring  them  gently  and  sift  over  them  a  mixture  of  finely  pulverized 
tripoli  and  pumice  stone.  The  moist  rags  are  piled  upon  each 
other,  placing  a  layer  of  the  powder  between  each  two.  They  are 
then  pressed,  taken  apart  and  dried. 

Belgian  Polishing  Powder,  which  is  recommended  for  polishing 
articles  of  silver,  consists  of  a  mixture  of  whiting,  250  parts ; 
elutriated  pipe-clay,  117;  white  lead,  62;  white  magnesia,  23; 
and  jewellers’  red,  23. 

For  Cleansing  Iron  and  Steel  Objects  finer  grades  of  emery-cloth 
are  very  suitable.  For  polished  iron  and  steel  articles  it  is  best  to 
use  tin-putty  and  prepared  hartshorn  triturated  with  spirits  of  wine 
and  applied  with  soft  leather. 

For  Soft  Metals  {Tin  and  Britannia  Wares)  the  dried  pistil  of 
shave-grass,  which  is  rich  in  silica,  is  very  suitable. 

For  Cleansing  Silverware  the  most  simple  (chemically  acting) 
polishing  agent  is  sodium  hyposulphite.  Moisten  a  rag  or  brush 
with  a  saturated  solution  of  the  salt.  Still  better  in  its  action  is 
a  fluid  of  water,  40  parts  ;  sodium  hyposulphite,  4  ;  sal-ammoniac, 
2;  and  caustic  ammonia,  1.  This  fluid  maybe  used  cold  and 
it  is  not  necessary  to  previously  free  the  articles  from  grease  with 
soda  or  potash  lye. 

For  Cleansing  Silver  Ornaments  use  a  boiling  hot  solution  of 
tartar  or  wrap  them  around  with  zinc  wire  and  boil  them  in  a  solu¬ 
tion  of  1  part  of  borax  in  10  of  water.  In  both  cases  the  articles 
must  be  previously  cleansed  with  soda  lye. 

Polishing  Powders  for  Silver. — I.  Mix  intimately  finely  pul¬ 
verized  cream  of  tartar,  4  parts  ;  flake  white,  8  ;  pulverized  alum,  2. 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


271 


Knead  the  mixture  into  a  stiff  paste  with  strong  wine  vinegar  and 
dry  it  in  the  air.  Then  pulverize  the  dry  mass,  knead  it  again 
to  a  paste  with  wine  vinegar,  repeat  the  process  once  more  after 
drying  and  lastly  pulverize  the  mass  obtained. 

II.  Mix  intimately  pulverized  hartshorn,  i  part ;  chalk,  5  ;  and 
jewellers’  red,  1. 

III.  Mix  intimately  by  sifting  xo  parts  of  fine  whiting,  1  of  pul¬ 
verized  soda  and  %  of  pulverized  citric  acid.  For  use  moisten 
the  powder  with  water  so  that  the  soda  and  citric  acid  dissolve  and 
act  chemically  upon  the  silver. 

English  Silver  Soap. — This  polishing  agent,  by  means  of  which 
and  the  use  of  a  brush  a  nice  lustre  is  imparted  to  silver  articles,  is 
prepared  as  follows:  Dissolve  2  parts  of  Castile  (pure  olive  oil) 
soap  in  2  parts  of  soft  water.  Take  the  soap-paste  formed  from  the 
fire,  stir  into  it  6  parts  of  fine  whiting,  pour  the  soap  into  moulds, 
and  allow  it  to  cool. 

Rose-color  English  Silver  Soap. — This  is  prepared  in  a  similar 
manner  as  the  foregoing,  but  instead  of  mixing  the  soap-paste  with 
whiting,  add  2  parts  of  finest  quality  of  white  tripoli,  3  of  pulverized 
chalk,  and  1  of  jewellers’  red.  Before  pouring  the  soap  into  moulds 
perfume  it  with  a  few  drops  of  oil  of  lavender,  which  imparts  to  it 
a  very  fine  odor,  and  renders  it  more  salable  than  soap  without 
perfume. 

Polishing  Balls  for  Silver. — This  polishing  agent  is  a  powder 
brought  into  the  form  of  a  ball  by  means  of  an  agglutinant.  It  is 
prepared  by  intimately  mixing  2  parts  of  yellow  tripoli  and  3  parts 
of  whiting,  kneading  the  mixture  with  a  solution  of  1  part  of  gum- 
arabic  in  12  of  water  to  a  stiff  paste,  and  finally  forming  the  latter 
with  the  hands  into  balls  the  size  of  a  pigeon  egg.  These  balls  are 
dried  upon  boards  in  a  moderately  warm  room,  and,  when  perfectly 
solid,  are  packed  in  tin-foil. 

Polishing-paste  for  Silver. — Perfume  3  parts  of  vaseline  with  a 
few  drops  of  nitrobenzol  (essence  of  mirbane),  and  stir  into  it  5 
parts  of  whiting,  1  of  burnt  hartshorn,  and  1  of  pulverized  cuttle- 
bone,  so  that  an  intimate  mixture  of  the  consistency  of  butter  is 
formed.  Put  into  small  tin  boxes. 


272 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


Polishing  Powder  for  Gold-workers. — Mix  together  4.3  parts  of 
carbonate  of  lead  (basic  white  lead),  17.4  of  chalk,  1.7  of  carbon¬ 
ate  of  magnesia,  4.3  of  alumina,  2.6  of  silica,  and  1.7  of  jewellers’ 
red. 

Polishing  Powder  for  Gold  Articles. — Dissolve  iron  filings  in 
hydrochloric  acid  until  the  development  of  gas  ceases,  and  then 
compound  the  resulting  chloride  of  iron  with  liquid  ammo¬ 
nia  as  long  as  a  precipitate  is  formed.  Collect  the  precipitate 
upon  a  filter  and  dry  it,  without  further  washing,  at  a  tempera¬ 
ture  at  which  the  adhering  ammonia  does  not  volatilize.  By  these 
means  the  ferrous  oxide  originally  precipitated  is  converted  into 
ferric  oxide,  and  the  mixture  contains  about  70  per  cent,  of  ferric 
oxide  and  30  per  cent,  of  ammonia.  It  forms  a  very  good  polishing 
powder. 

Polishing  Paste  for  Brass. — Dissolve  15  parts  of  oxalic  acid  in 
120  of  boiling  water,  and  add  500  parts  of  pumice  powder,  7  of  oil 
of  turpentine,  60  of  soft  soap,  and  65  of  any  kind  of  fat  oil. 

To  Cleanse  Brass  Articles  which  have  become  so  dirty  by  smoke 
and  heat  that  they  cannot  be  cleansed  with  oxalic  acid,  proceed  as 
follows :  Rub  them  first  with  potash  lye,  then  immerse  them  in  a 
mixture  of  equal  parts  of  nitric  and  sulphuric  acids  and  water,  and 
after  washing  and  rinsing  in  water,  dry  and  polish. 

To  Cleanse  Old  Brass. — To  cleanse  old  brass,  especially  small 
figures,  sword-hilts,  mountings,  etc.,  immerse  them  in  a  mixture  of 

1  part  of  nitric  acid  and  y2  part  of  sulphuric  acid.  Take  them  out 
after  a  short  time,  rinse  thoroughly  in  cold  water,  dry  in  sawdust, 
and  finally  polish  with  finely  pulverized  Vienna  lime.  The  articles 
will  appear  like  new. 

Polishing  Soaps. — I.  Stir  into  25  lbs.  of  liquid  cocoanut-oil  soap 

2  lbs.  of  tripoli,  and  1  lb.  each  of  pulverized  alum,  tartaric  acid, 
and  white-lead. 

II.  Stir  into  25  lbs.  of  liquid  cocoanut-oil  soap  5  lbs.  of  col- 
cothar  and  1  lb.  of  ammonium  carbonate. 

III.  Mix  25  lbs.  of  liquid  cocoanut-oil  soap  with  4  to  5  lbs.  of 
calcined  oxalate  of  iron. 

IV.  Stir  together  in  the  customary  manner  24  lbs.  of  cocoanut  oil 


CLEANSING,  GKINDING,  PICKLING,  POLISHING. 


273 


with  12  lbs.  of  lye  of  38  to  40°  B6.,  and,  when  the  mass  is  bright, 
stir  into  it  3  lbs.  of  colcothar,  mixed  with  3  lbs.  of  water  and  1.12 
ozs.  of  spirit  of  sal-ammoniac. 

The  polishing  soaps  are  cut  into  suitable  pieces,  stamped,  and 
brought  into  commerce  provided  with  directions  for  use.  These 
directions  are  generally  to  the  effect  to  apply  a  small  quantity  of  the 
soap  by  means  of  a  flannel  rag  moistened  with  water  to  the  article 
to  be  polished,  and  rub  until  the  desired  lustre  is  produced. 

Kratzer,  of  Leipzig,  gives  the  following  directions  for  polishing 
soaps  as  substitutes  for  polishing  pomades  :  I.  Pulverize  as  finely  as 
possible  332  parts  of  white  bole  or  chalk,  332  of  tartaric  acid,  and 
265  of  infusorial  earth.  Free  the  bole  or  chalk  and  the  infusorial 
earth  from  adhering  pebbles  by  sifting.  Pour  water  over  the  sifted 
mass  in  a  vessel,  stir  thoroughly,  and  after  3  or  4  minutes  pour  off 
the  bole,  etc.,  which  is  finely  divided  in  the  water,  and  repeat  the 
operation.  The  bole,  etc.,  is  then  allowed  to  settle,  and  after 
carefully  decanting  off  the  supernatant  water,  the  sediment  is  placed 
upon  a  filter  and  completely  dried  upon  a  stove.  To  the  ingredi¬ 
ents  thus  prepared  add  200  parts  of  glycerin,  200  of  water,  and  25 
of  alcohol.  The  polishing  soap  thus  prepared  is  poured  into  tin 
boxes  or  moulds. 

II.  Mix  5  lbs.  of  cocoanut  oil  with  8  lbs.  of  soda  lye  of  230  Be., 
and  boil  the  mixture  until  a  clear  glue-like  mass  is  formed.  When 
the  soap  is  sufficiently  solid  add  1  lb.  of  chalk  and  ^  lb.  each  of 
white-lead,  tartar,  and  alum,  all  previously  converted  into  a  fine 
powder,  and  pour  the  mass  into  small  moulds  about  10  inches  long, 
and  open  on  top  and  bottom  so  that  the  cold  soap  can  be  more 
readily  removed.  For  convenience  sake,  commercial  cocoanut-oil 
soap  may  be  used  instead  of  preparing  the  soap.  The  process  is  as 
follows-:  Convert  5^  lbs.  of  cocoanut-oil  soap  into  fine  shavings, 
and  melt  it  with  the  addition  of  some  water.  To  the  melted  soap 
add  then,  with  constant  stirring,  6.34  ozs.  of  chalk,  3  ozs.  of  alum, 
3  ozs.  of  tartar,  and  3  ozs.  of  white-lead,  all  previously  finely  pul¬ 
verized.  This  soap  is  also  poured  into  tin  moulds  open  on  top  and 
bottom,  and  taken  out  when  cold. 

Polishing-waier. — An  excellent  and  entirely  harmless  polishing- 
18 


274 


THE  METAL  WORKER’S  HANDY-BOOK. 


water  is  obtained  by  shaking  together  8.81  ozs.  of  whiting,  i  lb.  of 
alcohol,  and  1.12  drachms  of  spirit  of  sal-ammoniac. 

Polishing  (. Putz )  Pomades. — -I.  Melt  5  lbs.  of  lard  or  yellow 
vaseline,  and  stir  into  the  melted  mass  1  lb.  of  fine  colcothar. 

II.  Melt  2  lbs.  of  palm  oil  and  2  lbs.  of  vaseline,  and  stir  into 
the  melted  mass  1  lb.  of  ferric  oxide,  14. n  ozs.  of  tripoli  and 
oz.  of  oxalic  acid. 

III.  Heat  4  lbs.  of  American  mineral  oil  and  1  lb.  of  lard,  and 
stir  into  it  5  lbs.  of  fine  colcothar. 

The  polishing  pomades  are  generally  perfumed  with  nitrobenzole 
(essence  of  mirbane),  and  brought  into  commerce  in  small  tin 
boxes  provided  with  directions  for  use. 

Polishing  Cartridges  ( Putzpatronen) . — Moisten  50  parts  of  elutri. 
ated  quartz  or  infusorial  earth  and  10  of  emery-dust  with  100  parti 
of  a  30  per  cent,  gum  tragacanth  solution,  and  bring  the  whole  to 
a  suitable  consistency  with  soap  solution  (100  parts  of  soap  dissolved 
in  150  of  spirits  of  wine).  The  best  polishing  material  is  undoubt¬ 
edly  infusorial  earth,  either  by  itself  or  impregnated  with  oleic 
acid.  Infusorial  earth  by  itself  is  especially  suitable  ( or  polishing 
windows,  mirrors,  gold  and  silver  ware,  copper  and  brass  utensils, 
particularly  when  greasy. 

Polish  for  Pressed  Articles  of  Brass. — Substances  which  are  slimy 
without  being  actual  fats  are  better  adapted  for  this  purpose  than 
soap,  and  can  be  more  readily  removed  from  the  articles.  The 
best  polishing  agent  is  equal  volumes  of  water  and  ox-gall  boiled 
together.  When  cold  the  fluid  is  kept  in  well-corked  bottles,  and 
for  use  a  sufficient  quantity  is  poured  into  a  glass  or  porcelain  ves¬ 
sel.  It  is  applied  with  a  small  brush,  and  the  burnisher  is  also 
from  time  to  time  dipped  into  it. 

Rouge  for  Polishing  Metals. — As  the  rouge  found  in  the  market 
does  not  meet  the  requirements  of  the  workman,  at  least  for  every 
metal,  the  following  simple  method  is  given  which  allows  the  work¬ 
man  to  prepare  for  himself  just  the  quality  and  quantity  necessary 
for  his  particular  work.  Heat  sulphate  of  iron  (as  pure  a  quality 
as  can  be  obtained)  in  an  iron  vessel  over  a  slow  fire,  stirring  it 
continually  with  an  iron  spatula  till  it  is  dry  and  takes  the  form  of 


CLEANSING,  GRINDING,  PICKLING,  POLISHING. 


275 


a  pale  greenish-yellow  powder.  This  powder,  after  being  crushed 
in  a  mortar  and  sifted,  is  to  be  calcined  in  a  new  crucible  and  ex¬ 
posed  to  the  fire  of  a  smelting-stove  as  long  as  vapors  arise  from  it. 
As  soon  as  no  more  of  these  can  be  observed  the  contents  of  the 
crucible  may  be  left  to  cool,  and  when  cool  will  appear  like  the 
rouge  used  for  polishing.  Its  color  may  vary  from  pale  red  to 
brown  red,  or  even  to  blue  and  violet,  but  these  variations  arise 
only  from  the  different  degrees  of  heat  employed ;  and  it  may  be 
observed  that  the  higher  the  temperature  has  been  during  the  pro¬ 
cess  the  darker  the  color  and  the  harder  the  powder — a  fact  which 
also  explains  why  the  pale-red  powder  is  used  only  for  gold  and 
silver,  while  the  violet  is  employed  for  steel.  No  matter  what  the 
color  is,  it  is  very  important  that  the  rouge  be  well  bruised  and 
washed  in  water  before  it  is  used.  For  this  purpose  three  clean 
glasses  are  taken  and  one  of  them  is  filled  with  clean  water,  in 
which  a  part  of  the  rouge  is  mixed  by  stirring  it  for  some  time  with 
a  small  piece  of  wood.  After  allowing  about  half  a  minute  for  the 
rouge  to  settle  to  the  bottom  of  the  glass,  the  remainder  of  the 
(red)  liquid  is  decanted  into  the  second  glass,  but  every  particle  of 
the  deposit  must  be  left  in  the  first  one.  The  same  process  has  to 
be  observed  also  for  the  second  and  third  glasses,  but  with  this  dif¬ 
ference :  the  powder  in  the  second  glass  is  allowed  to  settle  about 
2  minutes,  while  in  the  third  one  it  is  left  for  several  hours,  that  is, 
until  the  water  assumes  its  natural  clearness.  The  sediment  of  the 
first  glass  is  almost  valueless,  that  of  the  second  of  medium  quality, 
but  that  of  the  third  glass  is  of  very  good  quality  and  fit  to  be 
used  with  great  advantage  after  it  has  been  slowly  dried.  In  some 
cases  the  rouge  thus  obtained  may  be  mixed  with  grease,  and  gener¬ 
ally  it  will  be  found  of  great  advantage  to  moisten  it  with  spirits 
of  wine  and  burn  it  in  a  clean  iron  vessel. 

To  Polish  Steel. — Rub  the  steel  with  a  piece  of  emery  paper  from 
which  you  have  removed  some  of  the  roughness  by  rubbing  it  on 
an  old  knife. 

To  Polish  Steel  Objects. — This  process  consists  in  polishing  the 
steel  objects  by  means  of  a  wheel  or  disk  made  of  16  parts  of  tin 
and  i  of  zinc,  to  the  flat  side  of  which  jewellers’  red  moistened 


276 


THE  METAL  WORKER’S  IIANDY-BOOK. 


with  alcohol  is  applied.  After  moderately  drying  the  objects  are 
burnished  with  an  agate. 

Lustreless  Surface  on  Steel. — A  finely-polished  lustreless  surface 
on  tempered  steel  may  be  procured  by  either  of  the  following 
operations  :  After  the  steel  article  has  been  tempered  it  should  be 
rubbed  on  a  smooth  iron  surface  with  some  pulverized  oil  stone 
until  it  is  perfectly  smooth  and  even,  then  laid  upon  a  sheet  of 
white  paper  and  rubbed  back  and  forth  until  it  acquires  a  fine  dead 
polish.  Any  screw-holes  or  depressions  in  the  steel  must  be  cleaned 
and  polished  beforehand  with  a  piece  of  wood  and  oil  stone.  This 
delicate  lustreless  surface  is  quite  sensitive  and  should  be  rinsed 
with  pure  soft  water  only.  A  more  durable  polish  is  obtained  by 
first  smoothing  the  steel  surface  with  an  iron  polisher  and  some 
powdered  oil  stone,  carefully  washing  and  rinsing.  Then  mix  in 
a  small  vessel  some  fresh  oil  and  powdered  oil  stone,  dip  into  this 
mixture  the  end  of  a  piece  of  elder  pith,  and  polish  the  steel  sur¬ 
face  with  a  gentle  pressure,  cutting  off  the  end  of  the  pith  as  it  be¬ 
comes  soiled.  In  conclusion,  it  should  be  thoroughly  cleaned  in 
soft  water,  when  the  article  will  be  found  to  have  a  fine  white, 
lustreless  polish. 

To  Polish  and  Color  Copper. — To  polish  copper  parts  rub  them 
with  rotten  stone  and  oil,  next  with  a  flannel  rag  and  finally  with 
leather.  A  solution  of  oxalic  acid  applied  to  dull  brass  soon  re¬ 
moves  the  layer  of  oxide  and  uncovers  the  metal.  The  acid  is  then 
washed  off  with  water,  and  the  brass  rubbed  with  soft  leather.  A 
mixture  of  hydrochloric  acid  with  alum  triturated  with  water  gives 
to  articles,  immersed  in  this  solution  for  a  few  seconds,  a  golden 
color.  An  orange-color  playing  into  gold  is  imparted  to  polished 
copper  by  immersing  it  for  a  few  seconds  in  a  solution  of  crystal¬ 
lized  acetate  of  copper.  A  beautiful  violet  color  is  obtained  by 
immersing  the  metal  for  a  few  seconds  in  a  solution  of  chloride  of 
antimony  and  then  rubbing  with  a  stick  wrapped  around  with  cot¬ 
ton.  During  this  operation  the  copper  must  be  heated  to  the  tem¬ 
perature  of  the  hand.  A  crystalline  appearance  is  produced  by 
boiling  the  article  in  solution  of  blue  vitriol. 

To  Cleanse  Dirty  Polishing  Leather. — Prepare  a  weak  solution 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  277 


of  soda  in  warm  water,  rub  some  soap  into  the  leather  and  let  it 
soak  two  hours;  then  wash  it  until  clean  and  finally  rinse  it  in  a 
solution  of  soda  and  yellow  soap  in  water  to  keep  it  soft.  By  wash¬ 
ing  in  water  alone  the  leather  becomes  hard  and  useless,  but  the 
small  quantity  of  soap  which  remains  in  the  leather  and  penetrates 
the  finest  portions  renders  it  soft  as  silk.  After  rinsing  wring  the 
leather  in  a  coarse  towel  and  dry  it  quickly;  when  dry  pull  it  in 
all  directions  and  brush  well.  By  these  means  a  softer  and  better 
leather  will  be  obtained  than  most  of  the  leathers  found  in  com¬ 
merce. 

In  using  a  rough  leather  to  go  over  highly  polished  surfaces  it 
will  be  frequently  observed  that  the  polish  is  injured.  This  is 
caused  by  particles  of  dust  and  even  grains  of  polishing-red  which 
remain  in  the  leath  Such  leather  should  be  thoroughly  brushed. 


X. 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING. 

Bronces  Incrustes  ( Incrustations ). — By  this  term  are  designated 
ornamentations  in  silver  or  gold  upon  a  body  of  massive  copper  or 
bronze.  The  body  is,  as  a  rule,  first  bronzed,  since  its  natural  tone 
of  color  is  generally  subject  to  change  by  atmospheric  influences 
and  does  not  present  a  good  contrast.  Copper,  for  instance,  is 
generally  bronzed  brown-red,  the  white  of  the  silver  contrasting 
well  with  it.  The  ornamentations  consist  partially  of  lines  and 
partially  of  planes,  calling  to  mind  niello  work.  While  in  the 
latter  the  noble  metal  is  mechanically  pressed  into  the  places  de¬ 
pressed  by  engraving  or  roughened  with  a  file,  in  incrusting,  as 
executed  by  Christofle,  of  Paris,  the  deposition  of  the  metal  is  effected 
by  galvanic  precipitation.  The  process  is  as  follows  :  The  design 
which  is  to  be  incrusted  in  silver  or  gold  upon  a  metal  is  executed 
with  a  pigment  of  white-lead  and  glue-water  or  gum-water.  The 
portion  not  covered  by  the  design  is  then  coated  with  a  varnish. 
The  article  is  next  placed  in  dilute  nitric  acid,  whereby  the  pig- 


278 


TTTE  METAL  WORKER’S  HANDY-BOOK. 


ment  is  first  dissolved,  and,  next,  the  surface  etched,  which  is 
allowed  to  progress  to  a  certain  depth.  Etching  being  finished  the 
article  is  washed  in  abundance  of  water  and  immediately  brought 
into  a  silver  or  gold  bath,  in  which,  by  the  action  of  the  current,  the 
exposed  places  are  filled  up  with  metal.  The  varnish  is  now  com¬ 
pletely  removed  with  benzine  and  the  entire  surface  ground  smooth. 
The  contours  are  quite  sharp.  The  surface  of  the  body  is  then 
bronzed,  which,  however,  does  not  change  the  tone  of  the  silver 
or  gold.  An  especially  beautiful  effect  is  produced  by  bronzing 
separate  portions  of  the  surface,  between  the  silver  ornamentation, 
black  with  sulphide  of  copper.  A  vessel  thus  decorated  then  shows 
three  tones  of  color,  viz.  :  the  design  in  white  and  black  upon  the 
agreeable  brown-red  .ground  of  cuprous  oxide.  The  principal 
requisite  for  the  production  of  these  incrustations  is  manual  skill 
and  much  patience ;  expensive  apparatus  is  not  required,  every 
skilled  electro-plater  being  able  to  execute  the  work. 

According  to  the  patented  process  of  Marie  Tessin  du  Motay, 
the  portions  to  be  provided  with  incrustations  are  not  only  pro¬ 
duced  by  etching  but  also  by  stamping  and  pressing.  In  the  latter 
case  the  metals  which  are  to  represent  the  design  may.be  precipitated 
either  before  or  after  pressing.  If  the  precipitation  takes  place 
before  pressing  the  relief  of  the  stamps  used  must  correspond  to  the 
greater  or  smaller  layer  of  metal  precipitated. 

Corvin's  Niello. — On  account  of  the  laborious  work,  and  slight 
durability  of  the  ornamentation,  the  decoration  of  metallic  surfaces 
by  inlaying  with  colored  lamina  of  mother-of-pearl,  amber,  ivory 
and  tortoise-shell  has  been  seldom  executed,  though  by  a  combina¬ 
tion  of  the  iridescent  mother-of-pearl  with  the  various  metallic 
lustres  the  most  splendid  articles  of  art  can  be  produced.  After 
many  years  of  labor  Corvin-Wierbitzky  has  succeeded  in  producing 
such  works  by  galvanoplasty,  and  has  patented  the  following  pro¬ 
cess  :  He  first  makes  a  matrice  of  metal,  whose  surface  is  finely 
polished.  This  matrice  may  be  used  for  the  production  of  numerous 
duplicates  of  the  same  kind  of  basin  or  other  objects.  The 
incrustations  (mother-of-pearl,  glass,  ivory,  amber,  etc.)  are  then 
shaped  by  means  of  a  saw,  files  and  other  tools  to  the  form  cor- 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  279 


responding  to  that  which  they  are  to  occupy  in  the  design.  The  side 
of  the  incrustations  which  is  laid  upon  the  matrice  is  as  a  rule  smooth. 
The  shaped  incrustations,  smooth  side  down,  are  pasted  on  to  the 
parts  of  the  model  they  are  to  occupy  in  the  design.  The  latter 
being  in  this  manner  produced,  the  back  of  the  non-metallic 
lamina  is  prepared  so  as  to  conduct  the  galvanic  current.  By  now 
placing  the  matrice  thus  prepared  in  the  galvano-plastic  apparatus, 
the  copper  precipitates  not  only  upon  the  metallic  matrice,  but  also 
upon  the  back  of  the  inlaid  pieces,  the  latter  being  firmly  enclosed 
by  the  precipitated  metal.  When  the  deposit  of  metal  has  the 
desired  thickness  it  is  detached  from  the  slightly-heated  matrice, 
and  incrustations  with  the  right  side  polished  are  thus  obtained. 
The  lamina  are  more  accurately  and  evenly  laid  in  than  would  be 
possible  by  the  most  skilful  hand-work.  The  articles  may  then  be 
further  decorated  by  engraving,  gilding,  silvering,  etc. 

Damaskeening. — Damascus  steel  is  a  special  kind  of  carbon  steel 
which  is  manufactured  according  to  Anossow’s  process  in  Slatust 
in  the  Ural.  The  sword  blades  celebrated  for  centuries  for  their 
good  qualities  derive  their  name  from  Damascus  in  Asia  Minor,  but 
nothing  is  known  about  their  manufacture.  It  has  been  tried,  as 
will  be  explained  later  on,  to  imitate  the  damask  by  welding 
together  strips  of  iron  and  steel,  but,  though  the  designs  were 
quite  beautiful,  genuine  damask  was  not  obtained.  The  designs  of 
damask  consist  of  a  peculiar  net-work  of  light  lines  standing  out 
from  a  dark  ground,  and  showing  either  a  moire  striped  lengthwise 
or  wavy  or  net-like  or  ribbon-like.  A  good  Damascus  blade  will 
cut  an-  iron  nail  without  suffering  injury.  For  the  production  of 
Damascus  steel,  according  to  Anossow’s  process,  iron  together  with 
graphite  and  a  flux  is  melted  in  a  crucible.  The  cake  of  steel 
found  after  cooling  upon  the  bottom  of  the  crucible  shows  already 
a  damaskeened  surface,  and  is  then  carefully  worked  further  in  the 
ordinary  manner. 

Imitation  of  Damascus  Steel. — Cut  8  sheets  of  steel  12  inches 
long,  1  inch  wide  and  T*2  inch  thick.  Now  prepare  5  sheets  of 
soft  iron  and  4  of  brittle  iron  of  equal  dimensions  with  the  steel 
sheets.  These  are  then  joined  together  in  the  following  manner : 


280 


TITE  METAL  WORKER’S  IIANDY-BOOK. 


A  sheet  of  steel  is  laid  upon  one  of  soft  iron,  upon  this  one 
of  brittle  iron,  then  one  of  steel,  and  so  on  to  the  seventh  sheet, 
which  should  be  one  of  soft  iron.  The  bundle  is  placed  in  the  fire, 
and,  after  moderately  heating,  welded  together.  It  is  then  squared 
and  worked  smooth  under  the  hammer  and  brought  to  a  white- 
heat.  One  end  is  then  placed  in  a  vise,  the  other  is  grasped  with 
a  pair  of  tongs  and  the  mass  vigorously  twisted  into  the  shape  of  a 
screw.  It  is  then  smoothed  and  wrought  into  a  bar  y2  to  y  inch 
wide  and  £  to  y,  inch  thick.  This  is  cut  into  2  equal  parts.  A 
sheet  of  steel  inch  thick,  and  as  long  and  as  wide  as  one  of  the 
two  parts  of  the  prepared  bar,  is  cut  and  placed  between  the  two 
parts.  The  bundle  is  placed  in  the  fire  and  then  beaten  under  the 
hammer  to  the  thickness  required  for  the  articles  to  be  manufac¬ 
tured.  A  pickle  consisting  of  1  y2  pints  of  water,  1  oz.  of  nitric 
acid,  1  oz.  of  sal-ammoniac  and  4 y2  drachms  of  blue  vitriol  is  now 
prepared  in  a  copper  vessel.  Paint  the  places  which  are  not  to  be 
damaskeened  with  some  kind  of  varnish,  and  place  the  articles 
manufactured  from  the  prepared  bar  in  the  bath.  When  the 
pickle  has  taken  effect  they  are  removed,  rinsed  off  with  cold  water 
and  dried. 

Damascus  Gun-barrels. — The  best  known  varieties  of  damask 
are  the  “  rose  and  Bernard  damask.”  The  process  of  manufactur¬ 
ing  the  first  variety,  which  is  also  called  “  Turkish  ”  damask,  is 
shown  in  Fig.  19  A. 

Square  rods  of  the  thickness  of  a  lead-pencil  are  first  formed 
by  arranging  26  ribands  of  iron  and  mild  steel  as  thick  as  paper,  in 
alternate  layers,  welding  the  whole  together  and  twisting  it  like  a 
rope  by  securing  one  end  in  a  vise  and  grasping  the  other  with  a 
pair  of  tongs.  Six  such  twisted  rods  are  then  welded  together  as 
shown  at  A,  Fig.  19,  and  twisted  around  an  iron  tube  h.  These 
crude  barrels  are  worked,  while  hot,  under  the  hammer  until  all 
parts  are  uniformly  united.  When  the  barrel  is  finished  the  tube 
around  which  the  riband  of  damask  is  twisted  is  bored  out.  The 
finished  barrel  is  filed  smooth  and  polished,  and  then  treated  with 
dilute  nitric  acid,  when  it  exhibits  a  diversified  laminated  structure, 
resembling  when  properly  managed  an  ostrich  feather. 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  2S1 


Barnard  damask  is  made  by  alternately  arranging  81  square  rods 
of  iron  and  steel  in  the  manner  of  a  chess-board,  B,  Fig.  19,  weld¬ 
ing  the  whole  together,  twisting  it  like  a  rope,  and  again  welding 
three  such  ropes  for  the  formation  of  the  riband,  which  is  then 
twisted  around  the  iron  tube.  Fig.  19,  C,  shows  the  design  of  the 
damask  of  a  double-barrel  gun.  In  this  case  the  iron  and  steel 
bands  are  placed  one  upon  the  other  before  heating  and  held 
together  by  wire. 

To  Damaskeen  Iron  and  Steel  with  Platinum. — Take  several  thin 
steel  sheets  or  alternately  steel  and  iron  sheets,  wrap  around  each 
a  platinum  wire,  and  after  placing  one  upon  the  other,  firmly 
tie  the  whole  together  with  steel  wire  in  such  a  manner  that 

J? 

u 


Fig.  19. 

the  last  wrappings  touch  each  other.  The  whole  is  then  welded 
together,  best  with  the  use  of  borax.  The  mass  thus  obtained  can 
then  be  worked  further  as  desired.  By  browning  or  bluing  the 
finished  article  the  lustrous  white  platinum  damask  appears  upon  a 
blue  or  brown  ground.  Instead  of  platinum  other  refractory 
metals,  for  instance,  nickel,  may  be  used. 

Damaskeening  with  Gold  or  Silver. — There  are  two  methods  of 
practising  this  process.  By  one  method  the  surface  of  the  metal 
to  be  damaskeened  is  roughened  with  a  file ;  the  artist,  by  skilful 
manipulation,  causes  to  adhere  to  the  roughened  surface  threads  of 
gold  or  silver,  which  are  pressed  down  and  burnished.  Broad  sur- 


282 


THE  METAL  WORKER’S  HANDY-BOOK. 


faces  are  produced  by  working  the  threads  or  wires  side  by  side. 
Heat  is  applied,  but  the  necessary  degree  requires  great  judgment. 
In  the  other  method  the  surface  to  be  damaskeened  is  incised  or 
cut  into,  the  incision  being  expanded  at  the  bottom.  Into  this 
channel  gold  or  silver  is  introduced  and  beaten  down. 

Imitation  of  Damask. — Prepare  a  mixture  of  equal  parts  of  good 
linseed  oil  varnish,  white  resin  and  wax.  Coat  with  this  the  iron, 
which  should  have  been  previously  cleansed  and  polished,  and 
draw  with  a  pen  the  pattern  usually  used  in  damaskeening.  Make 
a  rim  of  wax  around  the  pattern,  and  pour  nitric  acid  mixed  with 
an  equal  quantity  of  lemon  juice  upon  the  pattern.  As  soon  as 
the  nitric  acid  assumes  a  brownish  color  pour  it  off,  wash  the  iron 
thoroughly  with  water  and  remove  the  varnish  by  melting.  If  the 
article  is  small,  round,  or  has  an  uneven  surface,  place  it  for  a  few 
minutes  in  a  mixture  of  8  parts  of  water,  i  of  nitric  acid,  and  i 
of  lemon  juice,  and  allow  it  to  remain  until  the  fluid  assumes  a 
brownish  color,  when  it  is  taken  out  and  cleansed. 

To  Produce  Damask  in  Relief  upon  Gun  Barrels. — Carefully 
close  all  openings  of  the  barrel  with  corks  and  cleanse  it  from 
adhering  grease.  Then  place  it  in  a  box,  pitched  inside,  and 
pour  over  it  one  quart  of  water  previously  mixed  with  i  oz.  of 
hydrochloric  acid.  The  barrel  remains  in  this  mixture  for  3  to  4 
hours,  when  it  is  taken  from  the  box,  washed  with  water,  next 
rubbed  with  tow  dipped  in  tripoli  and  finally  thoroughly  dried. 
It  is  then  oiled  and  heated  over  a  coal-fire.  In  consequence  of 
this  treatment  the  steel  portions  appear  in  relief,  the  iron  portions 
having  been  attacked  by  the  corroding  solution. 

Damaskeened  Surface  upon  Steel-guns. — The  beautiful  damas¬ 
keened  surface  exhibited  by  the  Woolwich  and  Elswick  steel-guns 
is  produced  by  means  of  a  special  solution  composed  of  the  follow¬ 
ing  ingredients:  Tincture  of  steel,  2  ozs.  ;  nitric  acid,  1  oz.  ;  sul¬ 
phate  of  copper,  1  oz.  ;  spirit  of  nitre,  1^  ozs.  ;  spirits  of  wine, 
ozs. ;  and  water,  1  gallon.  This  solution  is  smeared  over  the 
parts,  and  when  dry  another  coat  is  put  on,  the  result  being  a  fine 
brown  color  which,  if  not  dark  enough,  is  made  so  by  a  repetition 
of  the  operation,  six  coats  being  sufficient  to  make  the  surface 


DECORATING,  ENAMELLING.  ENGRAVING,  ETCHING.  283 


black.  The  acid  is  then  killed  by  washing  with  soda  solution,  and 
the  whole  rubbed  with  a  hard  brush  until  smooth,  after  which  it  is 
rubbed  with  oily  waste.  Other  solutions  for  this  purpose  are  in 
use  at  some  establishments  of  high  repute,  one  of  the  most  im¬ 
portant  of  these  consisting  of  a  mixture  of  i  oz.  each  of  sulphur, 
tincture  of  steel,  nitric  acid  and  spirit  of  nitre  with  y  oz.  of  ‘ 
sulphuric  acid,  y2  oz.  each  of  mercuric  chloride  and  sulphate  of 
copper,  and  x  quart  of  water. 

Damasked  Bronze. — By  this  term  are  understood  bronze  articles 
engraved  with  quite  deep  lines  which  are  inlaid  with  silver  or  gold 
wire,  pressed  in  by  means  of  a  burnishing  stone  or  small  hammer. 
The  articles  are  finally  polished  and  have  a  beautiful  appearance, 
the  gold  and  silver  designs  upon  the  bronze  ground  presenting 
frequently  a  striking  resemblance  to  embroidery. 

Iridescent  Colors  upon  Metals. — To  produce  rainbow  colors  upon 
gilt  articles  of  iron,  brass,  and  other  metals,  as  well  as  upon  clean 
metallic  surfaces  in  general,  they  are  treated  as  follows :  Prepare  a 
bath  by  boiling  for  half  an  hour  3*4  ozs.  of  caustic  soda,  14^ 
drachms  of  litharge  and  1  quart  of  water.  Connect  the  object  to 
be  colored,  which  must  be  previously  thoroughly  cleansed  and 
pickled,  with  the  wire  of  the  positive  pole  of  a  battery,  and  use 
a  platinum  wire  as  anode.  By  dipping  the  platinum  wire  in  the 
bath  without  touching  the  article,  the  latter  becomes  immediately 
colored  with  various  colors  originating  from  a  more  or  less  thick 
layer  of  the  precipitated  oxide  of  lead.  Colors  of  all  possible 
contrast  can  be  obtained  by  placing  vertically  a  piece  of  stout 
parchment  paper  between  the  articles  to  be  colored  and  the  platinum 
wire,  and  also  by  providing  the  parchment  with  numerous  holes  or 
radical  segments. 

Moire  Metallique. — To  give  tin-plate  and  articles  manufactured 
from  it  a  crystalline  surface,  it  is  polished  by  hammering  and  then 
heated  over  a  coal-fire  so  that  the  tin  melts,  however,  without 
oxidizing.  It  is  then  removed,  and  the  side  which  had  been 
exposed  to  the  fire  is  poured  over  with  water  from  a  vessel  so 
arranged  that  a  broad  stream  can  be  brought  upon  the  surface.  In 
cooling  the  tin  crystallizes,  but  the  surface  presents  a  poor  appear- 


284 


THE  METAL  WORKER’S  HANDY-BOOK. 


ance,  and  must,  therefore,  be  further  treated  with  acid.  The  sheet 
is  placed  in  a  mixture  of  i  part  of  nitric  acid,  2  of  hydrochloric 
acid,  and  3  of  water,  whereby  the  tin  upon  the  surface  is  in  a  short 
time  dissolved.  The  sheet  is  then  taken  out,  washed  first  in  caustic 
potash-lye,  which  considerably  enhances  the  metallic  lustre,  and, 
after  rinsing  in  clean  water,  dried  at  a  moderate  heat,  and  finally 
coated  with  transparent  copal  lacquer.  By  certain  manipulations 
the  direction  the  crystallization  is  to  take  may  be  determined.  By 
drawing,  for  instance,  with  a  hot  soldering-iron  designs  upon  the 
back  of  the  heated  and  cooled  plate,  the  tin  melts  through  the 
plate,  and  by  the  action  of  the  acids  the  design  is  recognized  upon 
the  other  side  by  the  changed  direction  of  the  crystallization.  By 
heating  tinned  sheet-iron  over  the  flame  of  a  spirit-lamp  the  tin 
fuses  all  around,  and  forms  a  round  spot  whose  circumference 
becomes  the  larger  the  longer  the  sheet  remains  over  the  flame. 
On  removing  the  flame  the  place  where  it  was  applied  will  be 
recognized  as  the  centre  of  a  stellated  crystallization.  Pure  tin  is 
best  adapted  for  this  purpose.  The  moire  is  as  a  rule  obtained  by 
exposing  tin  or  tin-plate,  previously  carefully  cleansed,  to  the 
action  of  hydrochloric,  sulphuric,  or  nitric  acid,  or  other  chemical 
reagents  of  not  too  strong  action,  and  finally  freeing  the  surface 
covered  with  moire  as  much  as  possible  from  the  oxides  produced 
during  the  operation. 

I.  Pour  into  a  clean  and  dry  glass  or  porcelain  vessel  80  parts  by 
weight  of  ordinary  sulphuric  acid,  and  add  10  of  ammonium 
chloride,  sodium  chloride,  etc.,  and  immediately  cover  the  vessel 
with  the  sheet  to  be  treated,  allowing  it  to  remain  as  long  as 
effervescence  continues.  It  is  then  removed,  washed  by  immersing 
in  ordinary  water,  and  dried  with  fine  linen,  or  allowed  to  dry  by 
itself.  This  operation  is  repeated  five  or  six  times  in  succession 
until  a  moire  of  desired  purity  and  beauty  is  obtained. 

II.  By  immersing  tin-plate  in  sulphuric  or  hydrochloric  acid  for 
two  or  three  minutes  and  thoroughly  rinsing  in  ordinary  water,  it 
will  be  found  covered  with  moire. 

III.  A  very  white  and  lustrous  moire  is  obtained  by  boiling  tin¬ 
plate  in  sulphuric  acid  diluted  with  ten  times  its  volume  of  water 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  285 


for  half  an  hour,  then  rubbing  with  a  soft  woollen  rag  dipped  in  a 
solution  of  equal  volumes  of  cold  water  and  sulphuric  acid,  washing 
and  finally  rinsing  in  cold  water. 

IV.  First  wash  the  plate  with  a  soft  rag  saturated  with  a  mixture 
of  equal  volumes  of  alcohol  and  oil  of  turpentine.  After  thoroughly 
rubbing  the  entire  surface,  wash  with  pure  alcohol  and  dry  with 
clean  linen.  Now  take  the  yelks  of  12  fresh  eggs,  and  rub  them 
up  carefully  in  a  mixture  of  12  teaspoonfuls  of  hydrochloric  acid 
and  a  like  quantity  of  water.  When  the  composition  has  acquired 
the  consistency  of  a  stiff  paste,  add  12  teaspoonfuls  of  nitric  acid, 
which  renders  the  mixture  more  fluid.  Now  dip  a  pad  of  cotton  or 
other  soft  stuff  in  the  fluid,  and  rub  the  surface  of  the  metal,  being 
careful  to  carry  the  pad  quickly  and  lightly  over  all  parts,  so  that 
the  composition  is  everywhere  uniformly  applied,  but  not  allowed 
at  any  point,  to  dry.  When  the  designs  show  well  and  the  moire 
has  acquired  a  good  lustre,  so  that  neither  a  stain  or  an  inequality 
of  color  is  observed,  wash  with  a  woollen  rag  strongly  saturated 
with  a  mixture  of  equal  parts  of  hydrochloric  and  nitric  acids  and 
5  parts  of  water,  and,  after  washing  in  an  abundance  of  water,  allow 
the  article  to  dry.  By  adding  to  the  acid  mixture  diluted  with 
water  a  small  quantity  of  trichloride  of  gold,  the  gold  precipitates 
in  the  form  of  oxide,  and  imparts  to  the  moire  more  beauty  and 
lustre. 

Colored  Moire  on  Tin-plate. — Heat  the  tin-plate  to  a  temperature 
at  which  the  tin  begins  to  melt,  and  then  immerse  it  quickly  in  a 
fluid  composed  of  hydrochloric  acid,  2  parts  ;  nitric  acid,  1  ;  water, 
3 ;  and  potassium  bichromate,  1  ;  deep  black  spots  are  produced, 
which  become  still  darker  by  adding  some  tin  salt.  By  now  thor¬ 
oughly  rinsing  the  sheets,  pouring  hydrochloric  acid  over  them, 
which  is  allowed  to  run  slowly  from  the  sheets,  so  that  only  a 
slightly  acid  fluid  remains,  and  finally  pouring  over  a  solution  of 
10  parts  of  sodium  hyposulphite  in  120  of  water,  crystals  playing 
into  various  colors,  according  to  the  longer  or  shorter  time  of  the 
action  of  the  solution,  are  obtained.  The  articles  are  finally  rinsed 
in  water,  then  in  alcohol,  and  coated  with  a  suitable  varnish. 

Moire  on  Brass, — To  produce  moire  on  brass,  boil  the  objects  in 


286 


THE  METAL  WORKER’S  IIANDY-BOOK. 


a  concentrated  aqueous  solution  of  blue  vitriol  (i  part  blue  vitriol 
to  2  parts  water)  for  some  time.  The  shades  obtained  vary  accord¬ 
ing  to  the  proportion  of  zinc  and  copper  in  the  brass.  If  an  article 
when  taken  from  the  solution  appears  dark  red  or  dark  violet  with¬ 
out  perceptible  reflections,  it  is  only  necessary  to  rub  it  with  a  little 
wax-varnish  or  rosin-varnish.  The  formation  of  moire  is  much 
promoted  by  putting  a  few  small  pieces  of  iron  in  the  solution. 

To  Decorate  Tin-plate. — Lithographs  upon  tin-plate  or  other 
metal  sheets  are  frequently  produced  by  directly  printing  the  sheets 
in  the  lithographic  press.  More  elegant  results  are,  however, 
obtained  as  follows:  The  design  is  printed  in  black  color,  to  which 
some  copal  lacquer  has  been  added,  upon  sheets  of  paper,  the  size 
of  the  sheets  to  be  decorated,  which  have  been  prepared  with  paste, 
gum,  and  glycerin.  The  paper,  printed  side  down,  is  immediately 
laid  upon  the  sheet,  and  passed  together  with  it  through  the  press; 
it  is  then  dampened  with  a  wet  sponge,  and  again  passed  through 
the  press.  To  save  time,  the  production  of  the  lithograph  and  its 
transfer  to  the  metallic  sheet  is  frequently  combined  as  follows: 
Lay  the  paper  upon  the  stone,  upon  the  paper  a  leather-plate,  and 
upon  the  latter  the  sheet  with  the  last-printed  paper,  and  pass  the 
whole  through  the  press.  When  the  sheet  comes  from  the  press 
the  paper  is  again  dampened,  and  then  carefully  drawn  off,  whereby 
the  design  in  its  finest  details  remains  upon  the  sheet.  The  sheets 
are  now  placed  in  an  oven,  heated  to  284°  F.  for  12  hours,  then 
coated  with  a  mixture  of  copal  lacquer,  oil  of  turpentine,  and  lin¬ 
seed-oil  varnish,  and  again  placed  in  the  oven  for  12  hours.  When 
directly  printing  the  sheets  from  the  stone  some  asphalt  or  iron 
lacquer  is  added  to  the  printing-ink,  and  for  other  colors  some 
dammar  lacquer,  in  order  to  obtain  better  lustre  and  to  promote 
drying.  The  printed  sheets  are  dried  in  the  oven  until  the  color 
cannot  be  wiped  off,  care  being  had,  however,  not  to  raise  the 
temperature  to  the  melting-point  of  the  tin.  When  dry,  the  prints 
receive  by  means  of  a  flat,  broad,  soft  brush  a  uniform  and  not  too 
thick  coating  of  a  mixture  of  1  part  of  linseed  oil  and  2  parts  of 
dark  copal  lacquer,  and  are  then  again  dried  in  the  oven  for  one 
hour.  This  coating  imparts  to  the  sheets  the  lustre  and  color  of 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  287 


polished  brass ;  its  principal  advantage  being,  however,  that  it  does 
not  crack  off  when  bent,  so  that  the  decorated  sheets  can  be  worked 
in  every  way,  and  even  hammered. 

New  Method  of  Decorating  Metals. — This  invention  of  Nellie 
C.  Duncombe,  of  New  York  city,  presents  a  beautiful  field  for 
taste,  skill  and  industry,  and  it  has  been  carefully  fenced  in  by  the 
patent  issued  July  16,  1889.  The  decorative  design  is  formed 
upon  the  metallic  surface  by  means  of  etching  and  oxidation  of  the 
metal.  Suppose  the  plate  to  be  decorated  to  consist  of  polished  sheet 
brass,  all  those  portions  which  are  finally  to  appear  as  polished  sur¬ 
faces — the  high  lights  or,  perhaps,  the  outlines  of  the  design — are 
covered  with  a  brush  dipped  in  a  suitable  varnish.  When  the  var¬ 
nish  is  dry  the  plate  is  immersed  in  a  bath  of  nitric  acid  some¬ 
what  diluted,  in  which  is  a  small  piece  of  copper  in  process  of  dis¬ 
solution.  By  this  immersion  the  surface  of  the  plate  is  both  etched 
by  the  acid  and  discolored  by  the  action  of  the  copper  which  is 
dissolved  by  the  acid.  After  a  few  moments’  immersion  the  plate 
is  removed  and  rinsed.  As  it  dries  in  the  air  the  exposed  surface 
becomes  a  dull  brown,  like  old  bronze.  All  the  portions  that  are 
to  retain  this  color  are  then  painted  with  the  same  varnish  and  the 
plate  is  then  dipped  in  a  weak  solution  of  copper  salt.  This 
brightens  the  surface  and  gives  it  a  yellowish,  mottled  appearance. 
Then  the  plate  is  dried  in  fine  saw-dust,  box-wood  preferred.  After 
protecting  with  the  varnish  so  much  of  the  color  as  it  is  desired  to 
retain,  the  plate  is  again  immersed  in  the  same  nitric  acid  bath 
until  it  has  been  sufficiently  etched  to  remove  the  previous  oxida¬ 
tion,  again  rinsing  and  holding  it,  either  side  up,  over  a  tray  con¬ 
taining  diluted  nitric  acid  and  pieces  of  copper  and  sheet  brass. 
After  being  left  to  be  oxidized  in  these  fumes  a  few  moments,  the 
plate  is  again  dried  in  saw-dust,  and  the  result  is  an  orange-color 
somewhat  mottled.  Again  painted  and  exposed  for  a  longer  time 
to  the  fumes  of  the  acid,  copper  and  brass,  a  green  color  is  pro¬ 
duced.  Again  dried  in  the  saw-dust  and  painted  as  before,  a 
frosted  effect  is  produced  on  the  unpainted  portion  that  is  left  by  a 
quick  dip  in  a  bath  of  nitric  and  sulphuric  acids  and  water,  after 
which  it  is  rinsed  and  dried  quickly  in  hot  saw-dust. 


288 


THE  METAL  WORKER’S  HANDY-BOOK. 


The  varnish  is  now  removed  with  turpentine  or  another  solvent 
and  the  entire  design  is  exposed,  and  the  plate  is  completed. 

It  is  immaterial,  after  painting  over  the  high  lights,  in  what 
order  the  successive  oxidations  are  produced,  but  it  is  preferable  to 
oxidize  the  finer  and  more  delicate  portions  of  the  design  first 
and  finish  with  the  ground  etching.  The  depth  of  the  etchings 
is  of  no  consequence,  the  color,  like  beauty,  being  only  skin- 
deep. 

The  varnish  preferred  for  the  operation  is  made  as  follows  :  As¬ 
phalt,  2  ozs.  ;  white  wax,  i  y2  ozs.  ;  Burgundy  pitch,  i  oz.,  and  a 
sufficient  quantity  of  turpentine.  Melt  the  asphalt  in  a  glazed 
saucepan  and  add  the  wax  gradually,  stirring  with  a  glass  rod,  add 
the  pitch  and  continue  stirring,  permitting  it  to  boil  up  twice  or 
three  times,  but  never  let  it  boil  over.  Take  the  saucepan  from 
the  fire  and  stir  in  enough  turpentine  to  make  the  mass  the  con¬ 
sistency  of  tube  oil  paints.  Other  colors,  such  as  dark  purple  or 
orange,  red  and  green,  green  bronze  and  light  green,  bright 
green  and  red,  bright  pink,  iridescent  purple,  may  be  made  by  the 
same  method  with  various  kinds  of  baths. 

Nielled  Silver. — This  term  is  applied  to  silver  articles  provided 
with  a  black  etching.  The  articles  are  produced  by  first  engrav¬ 
ing  them  quite  deeply  and  inlaying  the  lines  with  a  black  enamel 
consisting  of  metallic  sulphide.  The  niel  consists  of  a  mixture  of 
sulphide  of  silver,  sulphide  of  copper  and  sulphide  of  lead.  The 
older  niel  was  generally  rich  in  silver,  but  in  the  modern  the  sul¬ 
phur  combinations  of  copper  and  lead  preponderate.  To  prepare 
the  niel  fuse  first  the  sulphur  in  a  graphite  crucible  and  heat  until 
the  sulphur  boils.  Heat  a  certain  quantity  of  silver  and  copper, 
which  are  best  used  in  the  form  of  wire  or  thin  sheet ;  throw  first 
the  silver  into  the  crucible,  then  the  copper  and  finally  the  lead, 
the  latter  in  pieces  the  size  of  a  pea.  Stir  the  mass  with  a  clay 
rod  to  intimately  mix  the  metallic  sulphides  and  examine  whether 
there  are  still  unmelted  parts  in  the  crucible.  When  all  is  melted 
pour  the  mass  quickly  into  water,  which  imparts  to  it  a  certain  de¬ 
gree  of  brittleness.  Then  powder  the  niel  as  finely  as  possible  in 
a  cast-iron  mortar,  separating  the  fine  from  the  coarse  powder  and 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  289 


again  pulverizing  the  latter.  The  proportions  generally  used  are  as 
follows : 

Parts. 


Silver .  8  2  i  x  2 

Copper . ...,i8  5  6  2  i 

Lead . 13  7  10  4 

Sulphur . . . 96  24  36  5  3 


According  to  Hart  the  niel  consists  of  4  parts  of  fine  silver,  9  of 
pure  copper,  1  of  platinum  (which  is,  however,  not  absolutely 
necessary),  2  of  borax  and  48  of  flowers  of  sulphur.  First  melt 
the  silver,  then  add  the  copper  and,  when  both  are  liquid,  the  lead. 
The  melted  metals  are  stirred  with  a  stick  of  charcoal  to  insure 
homogeneity.  The  mixture  is  then  poured  into  a  large  crucible 
containing  the  pulverized  sulphur.  The  crucible  is  then  replaced 
upon  the  fire  for  a  few  minutes  to  keep  the  mass  fluid.  It  is  then 
poured  over  brushwood  into  water  so  that  granules  are  formed. 
These  granules  are  collected,  dried  in  the  air  and  then  pulverized 
in  a  mortar. 

The  firm  of  Zachers,  of  Berlin,  claim  to  have  discovered  the 
process  of  making  the  niel  called  Tula,  after  the  Russian  town  of 
the  same  name.  According  to  them  the  niel  is  prepared  from  9 
parts  of  silver,  1  of  copper,  1  of  lead  and  1  of  bismuth.  The 
metals  are  melted  and  saturated  with  sulphur.  This  mixture  gives 
the  splendid  blue  which  was  formerly  erroneously  considered  as 
steel-blue. 

The  article  to  be  nielled  having  been  prepared  with  the  graver, 
by  etching  or  stamping,  is  then  dipped  in  a  solution  of  borax. 
The  pulverized  niel  is  next  made  into  a  stiff  paste  with  a  concen¬ 
trated  solution  of  sal-ammoniac  and  pressed  into  the  hollows  by 
means  of  a  spatula  or  brush.  After  wiping  off  the  excess  of  niel 
with  a  moist  cloth  the  article  is  allowed  to  dry,  after  which  it  is  to 
be  heated. 

This  is  effected  with  single  small  objects  over  glowing  coals,  but 
if  a  larger  number  of  objects  are  to  be  treated  they  are  placed  upon 
sheet-iron  and  brought  into  the  glowing  muffle  of  an  enamelling 
furnace.  When  the  niel  is  fused  the  iron  plate  with  the  articles  is 
19 


290 


THE  METAL  WORKER’S  HANDY-BOOK. 


taken  out  and  after  cooling  the  pattern  is  uncovered  by  a  level 
grinding  with  pumice  stone,  when  the  silver  will  appear  as  over  a 
black  ground.  Polishing  is  effected  with  the  same  agents  and  in 
the  same  manner  as  that  of  other  silver  objects.  A  cheaper  method 
than  by  engraving  each  article  by  itself  is  to  engrave  in  relief  a 
steel  plate  and  press  it  against  the  silver  plate  between  two  hard 
bodies.  The  copy  is  hollow  and  ready  to  receive  the  niel.  A 
great  many  copies  may  be  obtained  from  the  same  matrix. 

The  muffles  which  serve  for  the  reception  of  the  objects  to  be 


c  c 


Fig.  20. 


nielled  and  enamelled  consist  of  semi-cylindrical  bodies  generally 
made  of  refractory  clay.  On  one  of  the  wider  sides  they  are  pro¬ 
vided  with  a  large  opening  and  on  one  of  the  narrower  sides  with 
a  small  round  aperture.  The  large  aperture  is  closed  with  a  clay 
plate  after  the  objects  have  been  placed  in  the  muffle.  In  the 
small  aperture  is  secured  a  tube  which  can  be  closed  by  a  clay 
stopper.  By  removing  the  stopper  the  interior  of  the  muffle  can 
be  watched  through  the  tube,  and  the  burning  in  of  the  niel  or  en- 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  291 


amel  controlled.  An  enamelling  furnace  with  brass  muffle,  which 
is  very  suitable  for  working  on  a  small  scale,  is  shown  in  cross  sec¬ 
tions  at  Fig.  ?o ;  M  is  the  muffle  of  stout  sheet-brass.  It  is  pro¬ 
vided  on  one  side  with  a  lid  which,  with  its  projecting  edges,  can 
be  pushed  into  the  muffle.  The  furnace  is  constructed  of  double 
sheet-iron,  and  the  space  between  the  outer  casing  A  B  C  D  and 
the  inner  casing  c  is  filled  with  a  bad  conductor  (ashes,  etc.).  The 
casing  rests  upon  four  iron  legs  and  is  provided  at  d  e  with  a  small 
chimney.  The  muffle  rests  with  both  ends  upon  projecting  edges 
of  the  inner  casing.  The  furnace  is  heated  either  by  gas  or,  as  in- 


Fig  21. 


dicated  in  the  illustration,  by  spirit  flames.  The  size  of  the  muf¬ 
fle  as  well  as  of  the  entire  apparatus  depends  on  the  dimensions  of 
the  largest  article  to  be  decorated. 

Another  muffle-furnace  is  shown  in  Fig.  21.  O  is  the  actual 
furnace  of  refractory  material,  M  the  clay  muffle  resting  either 
upon  wrought-iron  rails  or  upon  projections  of  the  furnace  wall. 
R  is  the  grate,  A  the  ash-pit  and  B  the  aperture  for  introducing  the 
fuel.  In  front  of  the  muffle  is  a  day  plate  P  which  serves  as  a 
table  in  introducing  and  withdrawing  the  articles  to  be  enamelled. 


THE  METAL  WORKER’S  HANDY-BOOK. 


202 


To  Imitate  Nielled  Work  by  the  Galvanic  Method. — The  design 
is  executed  upon  the  silver  surface  with  a  pigment  consisting  of 
white-lead  and  glue  or  gum  water.  The  portions  which  are  to 
remain  free  are  coated  with  a  protecting  varnish  and  the  design  is 
then  uncovered  by  etching  with  very  dilute  nitric  acid.  The  ar¬ 
ticle  is  then  brought  as  the  anode  into  a  dilute  solution  of  ammonium 
sulphide,  and  a  small  platinum  sheet  connected  with  the  negative 
pole  is  dipped  into  the  solution.  Sulphide  of  silver  being  formed, 
the  design  becomes  quickly  black-gray  and,  after  removing  the 
protecting  varnish  with  benzine,  stands  out  in  sharp  contrast  with 
the  white  silver. 

Oxidized  Silver. — This  name  is  incorrect,  as  by  it  is  understood, 
riot  an  oxidation,  but  a  combination  with  sulphur  or  chlorine. 
Solution  of  pentasulphide  of  potassium  (liver  of  sulphur  of  the 
shops)  is  generally  used  for  oxidizing  silver.  Liver  of  sulphur  is 
prepared  by  intimately  mixing  and  heating  together  2  parts  of 
thoroughly  dried  potash  and  1  part  of  sulphur  powder.  Dissolve 
2  or  3  drachms  of  the  compound  in  0/2  pints  of  water,  and  bring 
the  liquid  to  a  temperature  of  from  1550  to  1750  F.,  when  it  is 
ready  for  use.  Silver  objects  previously  freed  from  dust  and  grease 
with  soda  lye  and  thorough  rinsing  in  water,  plunged  in  this  bath, 
are  instantly  covered  with  an  iridescent  film  of  silver  sulphide, 
which  in  a  few  seconds  more  becomes  blue-black.  The  objects  are 
then  removed,  rinsed  off  in  plenty  of  fresh  water,  scratch-brushed, 
and,  if  necessary,  polished.  It  is  advisable  to  use  the  oxidizing 
liquid  as  soon  as  prepared.  After  it  has  been  used  for  some  time 
the  deposit  becomes  dull  and  gray  and  lacking  in  adherence. 
There  is  danger  in  using  the  alkaline  liquid  too  strong;  the  coating 
will  form  more  quickly,  but  does  not  adhere  so  well. 

The  process  is  very  readily  executed  upon  pure  silver,  but  with 
articles  of  cupriferous  silver  the  result  is  not  quite  so  beautiful,  and 
it  is,  therefore,  advisable  to  subject  them  to  blanching  before 
oxidizing. 

A  velvety  black  color  is  obtained  by  dipping  the  article  previous 
to  oxidizing  in  solution  of  mercurous  nitrate,  by  which  it  becomes 
coated  with  a  thin  film  of  mercury,  which  forms  an  amalgam  with 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING. 


293 


the  silver.  When  brought  into  the  liver  of  sulphur  solution  a  mix¬ 
ture  of  mercury  sulphide  and  silver  sulphide  is  formed,  which  is 
much  darker  than  silver  sulphide  by  itself.  By  dipping  the  oxidized 
article  into  a  liquid  composed  of  io  parts  of  blue  vitriol,  5  of  sal- 
ammoniac,  and  100  of  vinegar,  the  places  of  the  silver  left  bright 
acquire  a  warm  brown  shade. 

Another  method  of  oxidation  is  effected  by  dipping  the  article  into 
diluted  chlorine  water,  chloride  of  lime  solution,  or  into  eau  de 
Javelle.  The  action  of  these  baths  is  based  upon  the  formation  of 
a  thin  layer  of  silver  chloride,  which,  on  exposure  to  light,  becomes 
dark. 

Beautiful  effects  and  tasty  designs  may  be  produced  by  combin¬ 
ing  various  shades  of  oxidation  with  the  bright  or  gilded  silver 
surface.  By  executing  the  design,  for  example,  with  asphalt 
lacquer  and  placing  the  articles  in  the  liver  of  sulphur  solution,  only 
the  places  left  free  become  oxidized,  and  the  result,  after  removing 
the  asphalt  lacquer  with  oil  of  turpentine,  will  be  a  white  design 
upon  a  dark  ground.  Dark  designs  upon  a  white  ground  are 
executed  with  ink  prepared  by  thickening  concentrated  liver  of 
sulphur  solution  by  the  addition  of  gum-arabic  solution.  When 
the  design  is  dry  the  article  is  heated  so  that  the  gum  cracks  off  or 
can  be  removed  by  a  gentle  tap.  Black  and  light  designs  upon  a 
dark  gray  ground  are  carried  out  by  executing  the  first  with  asphalt 
solution  and  the  latter  with  ink  composed  of  mercurous  nitrate  and 
gum-arabic  solution,  and  dipping  the  article  into  the  liver  of  sulphur 
bath. 

A  yellow  color  is  imparted  to  silver  articles  by  dipping  in  a  hot, 
concentrated  solution  of  cupric  chloride. 

A  deep  black  oxidized  surface  may  be  obtained  directly  on  cop¬ 
per ,  properly  cleansed,  by  immersion  in  a  concentrated  solution  of 
hydrous  carbonate  of  copper,  either  cold  or  tepid.  The  copper 
surface  at  once  becomes  coated  with  a  fine  black  deposit,  which  will 
stand  subsequent  treatment  very  well.  A  fine  oxidized  surface 
may  also  be  produced  by  depositing  on  the  surface  of  the  articles 
or  on  certain  portions  thereof  a  film  of  metallic  platinum.  For 
this  purpose  prepare  a  solution  of  platinic  chloride  in  sulphuric 


THE  METAL  WORKER’S  HANDY-BOOK. 


2D4 

ether  or  alcohol,  and  apply  the  solution  with  a  brush  to  the  parts 
of  the  surface  to  be  oxidized.  The  ether  or  alcohol  speedily  evap¬ 
orates,  leaving  behind  a  film  of  metallic  platinum  adhering  to  the 
surface  of  the  object,  which  film,  according  to  its  thickness,  imparts 
to  the  surface  either  a  steel-gray  or  nearly  black  lustre.  A  hot 
aqueous  solution  of  platinic  chloride  will  give  the  same  results. 

New  Protecting  Coat  on  "Metals. — Two  pounds  of  borate  of  lead 
are  ground  very  fine  with  water.  It  is  then  allowed  to  settle,  and, 
after  pouring  off  the  water,  the  deposit  is  mixed  with  a  precipitate’ 
of  platinum  obtained  by  the  addition  of  i)4  cubic  inches  of  am¬ 
monia  to  a  solution  of  63^  drachms  of  platinic  chloride  in  i  quart 
of  water,  allowed  to  settle  for  3  hours,  decanting  the  ammonia- 
water,  replacing  it  by  clean  water,  again  allowing  it  to  settle  for  3 
hours,  and  finally  decanting  the  water.  The  platinum  is  ground 
together  with  the  borate  of  lead  for  at  least  x/2  hour;  5  quarts  of 
water  are  then  added,  and  the  mass  is  ready  for  use.  The  articles 
of  iron,  steel,  or  copper  to  be  coated,  previously  brushed  or  washed, 
are  dipped  in  the  preparation,  or  coated  with  it  by  brushing,  and 
heated  in  a  strongly  heated  muffle,  or  by  a  gas  flame,  until  the 
originally  white  coating  has  acquired  the  color  of  dull  iron. 

Photo-chemical  Process  of  Decorating  Metal. — Breit,  of  Barmen, 
has  patented  in  Germany  a  process  according  to  which  the  metallic 
surface  to  be  decorated — tabbied  tin-plate  is  especially  suitable  for 
the  process — is  first  coated  with  a  colorless  or  colored  alcoholic 
lacquer,  and  then,  in  a  dark  room,  with  a  solution  of  chrome- 
gelatine.  The  latter  is  obtained  by  dissolving  5  to  10  parts  by 
weight  of  gelatine  and  1  to  2  of  bichromate  of  potash  in  100  of 
water.  The  gelatine  possesses  the  peculiarity  of  losing  its  solubility 
in  water  by  the  action  of  light.  Hence,  by  covering,  after  drying, 
the  plate  with  the  desired  pattern  and  exposing  it  in  a  copying 
frame  to  the  light,  the  layer  of  gelatine  on  the  places  exposed  to 
the  light  becomes  insoluble,  while  the  parts  covered  by  the  pattern 
can  be  removed  by  placing  the  plate  in  warm  water.  After  drying, 
the  layer  of  lacquer  first  applied  is  removed  from  the  places  freed 
from  gelatine  with  cold  spirit  of  wine.  The  gelatine  design 
remaining  upon  the  plate  may  be  colored  as  desired  by  placing  the 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING. 


295 


plate  in  a  dye-bath,  the  colored  designs  upon  a  bright  ground  thus 
obtained  being  fixed  by  lacquering.  Before  lacquering  the  metallic 
surfaces  may  be  suitably  provided  with  a  patina,  whereby  the  effect 
of  colored  designs  upon  a  differently  colored  ground  is  obtained. 

To  Prepare  Zinc  for  Painting. — Brush  over  the  zinc  with  a  solu¬ 
tion  of  i  part  each  of  chloride  of  copper,  nitrate  of  copper  and 
sal-ammoniac  in  64  parts  of  water  and  add  to  the  mixture  1  part 
of  commercial  hydrochloric  acid.  After  12  to  24  hours  the  solu¬ 
tion  dries  to  a  dull  gray  color.  Painting  upon  this  surface  the 
colors  will  adhere  in  a  perfect  manner.  Another  process  is  as 
follows:  Into  some  hydrochloric  acid  of  full  strength  drop 
pieces  of  zinc  until  effervescence  ceases.  Add  an  equal  quantity 
of  water  and  with  a  sponge  tied  to  a  stick  wash  over  every  part  of 
the  surface  to  be  painted.  This  roughens  the  surface  and  takes  off 
that  sort  of  greasiness  which  prevents  paint  from  adhering.  After 
the  acid  has  remained  a  short  time  on  the  zinc  wash  with  water  or 
dilute  vinegar,  dry,  and  paint. 

How  to  Prepare  a  Rough  Surface  in  Grounding  Metals  for  Sub¬ 
sequent  Decoration. — The  object  of  this  process  is  to  ground  metals 
which  are  to  be  enamelled,  or  decorated  with  vitrifiable  colors,  or 
protected  from  tarnishing  or  rusting.  The  preparation  of  the  sur¬ 
face  to  be  enamelled  is  very  simple  and  inexpensive;  the  enamel 
can  be  directly  and  uniformly  applied  without  the  necessity  of 
using  a  special  ground  mass  and  adheres  very  firmly  without 
cracking  or  peeling  off.  The  process  is  executed  as  follows  :  Mix 
finely  pulverized  iron-scale  (magnetic  oxide),  or,  still  better,  pure 
ferroso-ferric  oxide  prepared  by  precipitation,  with  more  or  less 
finely  pulverized  emery  and  triturate  the  mixture  with  a  solution 
of  lead  or  tin  soap,  adding  a  few  per  cent,  of  a  readily  fusible  frit. 
Apply  this  mass  to  the  metal  to  be  grounded  and  burn  it  in.  In 
burning  in,  the  article  may  be  heated  to  a  red  heat,  whereby  a  fine 
violet-blue  coating,  rough  to  the  touch,  is  obtained,  which,  with¬ 
out  further  preparation,  can  be  dipped  into  the  covering  mass,  en¬ 
amelled  or  painted  with  vitrifiable  colors,  and  burnt  in.  By  this 
treatment  the  rough  violet-blue  coating  formed  from  the  lead  solu¬ 
tion  and  the  magnetic  iron  mixed  with  emery  constitutes  the 


296 


THE  METAL  WORKER’S  II ANDY-BOOK. 


ground  mass  for  the  enamel  and  colors.  By  the  foregoing  described 
method  of  grounding,  articles  of  all  kinds,  of  cast-iron  as  well  as  of 
wrought-iron,  can  be  provided  with  a  very  durable  enamel.  By 
increasing  the  quantity  of  magnetic  iron  a  ground  mass  for  a  very 
refractory  covering  mass  may  be  made. 

To  Coat  Stoves,  Tools,  etc. — Metallic  tools  and  other  articles, 
particularly  those  of  iron  and  steel  which  are  used  in  laboratories 
and  other  workshops  where  acid  vapors  are  of  frequent  occurrence, 
can  be  protected  with  a  lustrous  black  coat  which  resists  acids,  and 
is  but  little  affected  even  by  a  low  red  heat,  as  follows:  Have  a 
sheet-iron  box  constructed  large  enough  to  hold  all  the  articles  to 
be  coated,  and  provided  with  a  false  bottom  of  wire  netting  about 
1 1/2  inches  above  the  actual  bottom.  Underneath  this  wire  netting 
is  placed  a  layer  of  crushed  blacksmith’s  coal  about  ^  inch  deep; 
then  place  the  articles,  which  must  be  entirely  free  from  rust,  clean 
and  polished,  upon  the  wire  net.  The  box  is  then  covered  with  a 
well-fitting  lid  and  set  on  a  strong  fire,  which  causes  the  coal  to 
give  off  tarry  constituents,  the  heat  being  continued  until  the  bot¬ 
tom  of  the  box  is  at  a  red  heat.  When  all  evolution  of  gas  has 
ceased  the  box  is  allowed  to  become  cold,  and  the  articles  are 
taken  out,  and  will  be  found  covered  with  a  beautiful  glossy  coat. 

Ward's  Inoxidizing  Process. — This  process  is  based  upon  the 
simultaneous  employment  of  silicates  and  heating.  The  cast-  or 
wrought-iron  articles  are  coated  by  means  of  a  brush  or  by  immer¬ 
sion  with  a  silicate.  This  coating  dries  quickly,  and  when  the 
articles  are  exposed  to  a  suitable  heat  liquefies,  penetrates  the  pores 
of  the  metal,  and  after  cooling  forms  a  dense  uniform  coating  of  a 
dead-black  color,  which  does  not  change  by  the  action  of  the 
atmosphere  nor  crack  off  from  the  article.  By  adding  to  the  sili¬ 
cate  pigments  used  for  coloring  glass,  decorated  surfaces  of  great 
beauty  may  be  obtained,  which  are  far  superior  to  those  produced 
in  the  ordinary  manner  by  the  application  of  paint. 

Inoxidizing  Process  for  Cast-iron. — The  cast-iron  articles,  entire 
gas-chandeliers,  water  pipes,  ornamental  pieces,  railings,  kitchen- 
pots,  etc.,  are  placed  upon  an  iron  carriage  and  first  exposed  in  a 
reverberatory  furnace  of  special  construction  at  a  temperature  of  from 


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DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  297 


m20  to  12920  F.  for  15  minutes  to  the  oxidizing,  and  then  for 
20  minutes  to  the  reducing  action  of  gas  generators.  After  removal 
from  the  furnace  and  cooling,  the  inoxidized  articles  acquire  a 
uniform  slate  color;  they  may,  however,  be  enamelled  and  deco¬ 
rated  in  any  manner  desired.  In  applying  the  enamels  pickling 
with  acid  is  not  necessary,  and  consequently  the  enamel  adheres 
very  firmly.  Various  articles  exposed  in  the  open  air  for  two  years 
to  all  kinds  of  atmospheric  influences  showed  no  trace  of  deteriora¬ 
tion.  Numerous  experiments  have  demonstrated  that  the  tensile 
strength  of  the  iron  is  but  little  decreased  by  inoxidation,  in  fact,  no 
more  than  by  annealing.  As  regards  the  durability  of  the  surface  layer 
with  a  high  load,  it  has  been  determined  that  from  wrought-iron 
bars  it  cracked  off  in  the  form  of  small  lamina  with  an  average 
tension  of  4025  lbs.,  but  from  cast-iron  it  did  not  crack  off  even 
with  a  breaking  load. 

The  Barff  Process  for  Preserving  Iron  and  Steel  from  Rust. — - 
Barffing  is  so  called  from  the  name  of  its  discoverer;  and  its 
purpose  is  to  render  the  surface  of  metallic  articles  treated,  resistant 
to  acids  and  impervious  to  humid  oxidation.  Iron  and  steel  that 
have  been  properly  barffed  will  not  rust.  The  process  belongs  in  no 
sense  to  the  chemical  laboratory,  and  requires  no  particular 
scientific  knowledge  or  technical  skill  for  its  success.  Highly 
polished  work  retains  its  finish  after  the  process,  although  the 
treatment  changes  the  shining  polish  to  a  dark  slate  color.  But 
working  parts,  such  as  sliding  and  rubbing  surfaces,  retain  their 
smoothness,  and  work  as  freely  after  as  before  the  process ;  plugs, 
valves,  and  stems  for  cocks,  gates  and  faucets,  for  instance,  working 
just  as  smoothly  as  though  they  had  not  been  barffed. 

The  articles  to  be  treated  are  made  perfectly  clean — free  from 
oil  and  dust — and  are  placed  in  a  muffle,  an  air-tight  oven,  into 
which  is  led  a  steam-pipe  from  a  boiler  that  carries  steam  at  a  press¬ 
ure  of  from  60  to  100  pounds  to  the  inch.  This  pipe,  after  leaving 
the  boiler,  becomes  a  coil  in  a  furnace  in  which  it  is  kept  at  a  red 
heat.  Of  course,  the  steam  that  is  discharged  into  the  muffle  is 
what  is  known  as  “red-hot  steam,”  or  steam  highly  superheated. 
The  effect  of  this  steam  on  the  articles  exposed  to  its  action  is  to 


298 


TITE  METAL  WORKER’S  ITANDY-ROOK. 


convert  their  surfaces  into  magnetic  oxide  of  iron,  this  change 
reaching  to  an  appreciable  depth,  giving  to  the  surface  the  hardness 
of  steel  with  the  durability  of  gun-metal.  It  has  been  said  that 
the  surface  of  the  metal  is  changed  to  an  “appreciable  depth,” 
perhaps  it  would  be  more  precise  to  say,  that  this  magnetic  oxide 
adds  to  the  surface ;  for  micrometer  tests  show  that  the  article  is 
absolutely  larger  after  being  barffed  than  before  undergoing  the 
process. 

Pieces  which  are  to  work  together,  therefore,  as  the  plug  and 
barrel  of  a  cock,  are  fitted  to  allow  for  this  increase,  the  plug  being 
finished  somewhat  smaller  than  it  would  have  been  if  it  was  to  be 
u^ed  in  its  lathe-finished  state.  The  only  limit  to  the  size  of  the 
pieces  to  be  barffed  is  the  capacity  of  the  muffle. 

Enamelling  Metals. — In  enamelling  metals,  transparent  or 
opaque,  colored  or  plain  enamels  are  fused  by  heat  upon  the  surface 
of  the  object  and  incorporated  by  fusion  with  its  surface.  Enamel 
for  metals  must,  therefore,  be  indestructible  by  heat.  A  good 
enamel  for  coating  iron  utensils  should  firmly  adhere  to  the  surface, 
withstand  slight  shocks  and  be  capable  of  resisting  changes  of 
temperature  and  chemical  influences.  Besides  it  should  not  be  too 
refractory  and  should  fuse  at  a  lower  temperature  than  the  metal  to  be 
coated.  To  enable  the  enamel  to  follow  the  expansion  and  con¬ 
traction  of  the  iron,  and  to  stand  changes  of  temperature,  two 
kinds  of  enamel  fusible  at  different  temperatures  are  applied  in 
enamelling  iron  utensils.  The  first  layer  is  called  ground  ox  ground 
mass,  and  consists  of  an  aluminium  silicate  containing  frequently 
as  much  as  75  per  cent,  of  silicic  acid.  The  refractoriness  of  the 
ground  mass  is  besides  frequently  decreased  by  the  addition  of 
boric  acid  and  alkalies,  and  its  adhesion  to  the  iron  promoted  by  a 
small  content  of  magnesia.  For  enamelling  articles  not  to  be  used 
for  culinary  purposes,  the  refractoriness  of  the  ground  mass  may  be 
decreased  by  the  addition  of  oxide  of  lead.  The  ingredients  for  the 
preparation  of  the  ground  mass  are  fused,  and  after  cooling,  pulver¬ 
ized  and  ground  until  a  uniform,  fine  powder  is  obtained. 

The  covering  mass,  ox  glaze,  contains  less  silica  and  alumina  and 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING. 


299 


is  therefore  more  readily  fusible  than  the  ground  mass.  It  is 
rendered  opaque  by  the  addition  of  zinc  oxide. 

Enamel  for  Iron  Objects. — An  enamel  for  cast  and  wrought-iron 
articles  is  obtained  by  fusing  together  130  parts  of  finely  pulverized 
crystal  glass,  20^  parts  of  calcined  soda  and  12  of  boric  acid, 
and  comminuting  and  finely  pulverizing  the  fused  mass.  This 
enamel  is  glass-like,  transparent  and  lasts  well  upon  sheet-iron. 
Several  layers  of  enamel  of  different  degrees  of  fusibility  may  also 
be  used  for  enamelling.  The  layer  coming  in  direct  contact  with 
the  iron  is  called  “ground-mass.”  It  fuses  but  incompletely,  only 
the  second  layer,  “  the  covering  mass,”  fusing  completely  and  im¬ 
parting  the  requisite  smoothness  to  the  glaze.  For  preparing  the 
ground-mass  fuse  together  30  parts  of  finely  ground  feldspar  with 
25  of  borax,  and  after  pulverizing  the  mass,  mix  it  with  10  parts  of 
clay,  6  of  feldspar  and  1^  of  carbonate  of  magnesia.  Mix  this 
ground-mass  with  water  to  a  paste  and  apply  it  to  the  object  to  be 
enamelled.  Then  scatter  upon  it  the  covering-mass  composed  of  a 
finely  powdered  and  fused  mixture  of  37^  parts  of  quartz  meal, 
2f/2  of  borax,  50  of  stannic  oxide,  15  of  soda  and  10  of  saltpetre. 
The  mass  is  uniformly  distributed  upon  the  object  to  be  enamelled, 
carefully  dried  and  burnt  in  in  the  muffle  furnace.  Other  directions, 
especially  for  sheet-iron,  are  as  follows  :  Silica  or  quartz,  30  to  50 
parts;  flint,  10  to  20;  or,  granite,  20  to  30  parts;  china  clay,  10 
to  20  ;  or,  borax,  16  to  20  parts;  pipe  clay,  8  to  10;  or,  glass,  6  to 
10  parts;  chalk,  6  to  10;  or,  magnesia,  10  to  15  parts;  porcelain 
meal,  5  to  15  ;  or,  feldspar,  5  to  20  parts;  boric  acid,  20  to  40  ; 
or,  carbonate  of  soda,  10  to  20  parts  ;  saltpetre  or  heavy  spar,  6  to 
10  ;  gypsum,  2  to  8  ;  fluorspar,  3  to  10.  After  fusing,  the  masses 
are  finely  ground  and  applied  in  thin  layers,  because  on  heating, 
the  enamel  and  sheet  expand  differently.  Cooling  must  also  be 
effected  very  slowly  since  by  cooling  off  too  rapidly  the  enamel 
contracts  unequally  and  cracks  off. 

To  Ena?nel  Cast-iron  Ute?isils. — This  is  done  in  Lower  Silesia 
by  means  of  two  masses,  one  for  a  ground  and  the  other  for  a 
surface  coat.  For  the  ground-mass  tio  lbs.  of  quartz,  50  lbs.  of 
borax  and  16^  lbs.  of  fluorspar  are  ground  as  fine  as  possible  and 


300 


THE  METAL  WORKER’S  HANDY-BOOK. 


fused  together  in  clay  crucibles.  Of  the  resulting  mass  35  lbs.  are 
then  mixed  with  14  to  27 y2  lbs.  of  quaitz,  9  to  14  lbs.  of  gray 
clay  and  1  lb.  of  borax.  The  composition  is  then,  with  water, 
formed  into  a  paste,  applied  to  the  vessels  and  burnt  in. 

For  the  surface  coat  the  following  ingredients  are  mixed  together  : 
Fluorspar,  5^  lbs.  ;  zinc  oxide,  2~y  ;  stannic  oxide,  10 y2  ;  bone 
meal,  \y2  smaltine,  1  to  iy  ozs.  To  this  are  added:  Fluor¬ 
spar,  35^  lbs.  ;  borax,  20  to  21^  lbs.  ;  sodium  carbonate,  7  lbs.  ; 
nitre,  2^  to  3^  lbs.  ;  and  the  mixture  is  fused  in  refractory  cru¬ 
cibles  with  a  hole  in  the  bottom  through  which  the  liquid  mass 
escapes  into  a  vessel  placed  beneath  the  furnace.  The  mass,  when 
,cold,  is  pounded  and  ground,  and  4  ozs.  of  washed  white  clay  and 
y2  lb.  of  zinc  oxide  are  added  during  the  grinding  process  to  every 
66  lbs.  of  the  mass.  The  composition  is  then  applied  like  the  first 
and  burnt  in. 

In  England  a  very  white  and  firmly  adhering  ena?nel  for  cast-iron 
articles  is  prepared  as  follows  :  Keep  the  articles  at  a  red  heat  in 
sand  for  y2  hour,  cool  off  slowly  and  cleanse  them  with  hot  dilute 
sulphuric  or  hydrochloric  acid,  then  rinse  in  water  and  dry.  Next 
apply  a  ground-mass  composed  of  flint  glass,  6  parts ;  borax,  3  ; 
minium,  1  ;  oxide  of  zinc,  1,  finely  powdered  and  roasted  at  a  red 
heat  for  4  hours,  then  rendered  semi-fluid  by  increased  temperature, 
then  cooled  in  cold  water  and  1  part  of  it  mixed  with  2  parts  of 
bone  meal  and  made  into  a  paste  with  water.  When  the  coating 
on  the  article  is  dry  apply  a  surface  coat  composed  of  a  mixture  of 
32  parts  of  calcined  bones,  16  of  china  clay,  14  of  feldspar,  4  of 
potash,  mixed  with  water,  dried,  cooled  and,  when  powdered, 
made  into  a  paste  with  16  parts  of  flint  glass,  $y  of  calcined 
bones,  and  3  of  calcined  quartz  with  sufficient  water.  When  this 
second  coat  is  dry,  apply  a  mixture  composed  of  4  parts  of  feld¬ 
spar,  4  of  pure  sand,  4  of  potash,  6  of  borax,  1  of  oxide  of  zinc, 
1  of  saltpetre,  1  of  white  arsenic  and  1  of  pure  chalk,  mixed, 
calcined  and  cooled,  and  rubbed  to  a  fine  powder  with  3^  parts 
of  calcined  bones  and  3  of  quartz.  The  coated  articles  are  heated 
in  a  muffle  in  a  furnace,  which  fuses  the  last  two  coatings  and 
forms  an  adhesive  and  brilliant  white  enamel. 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  301 


Another  Method  of  Enamelling  Cast-iron. — Scour  the  objects 
thoroughly  with  sand  and  dilute  acid,  rinse  in  water  and  dry. 
Then  apply  by  means  of  a  coarse  brush  a  thin  coat  of  gum-arabic, 
and  scatter  upon  this,  while  still  moist,  the  enamelling  powder. 
For  white  enamel  the  powder  consists  of  130  parts  of  pulverized 
flint  glass,  20  of  calcined  soda  and  12  of  borax,  fused  together  in 
a  crucible.  The  objects  strewn  over  with  this  powder  are  dried  at 
176°  F.,  and  the  powder  is  then  liquefied  in  a  suitably  heated 
furnace.  This  coating  adheres  well  and  contains  no  injurious 
substances. 

Mottled  Enamel. —  The  composition  of  the  enamel  is  as  follows  : 
Silica,  100  lbs.  ;  soda-ash,  35  lbs.  ;  borax,  75  lbs.  ;  plaster  of  Paris 
or  gypsum,  10  to  20  lbs.  ;  and  arsenious  acid  in  the  proportion  of 
per  cent,  of  all  the  other  ingredients.  When  these  are  com¬ 
pounded  the  resulting  mixture  is  an  enamel  vitreous  enough  to 
carry  a  glaze  of  itself,  with  an  affinity  for  wrought  or  sheet-iron 
which  causes  it  to  adhere  with  extreme  tenacity  when  burned  upon 
it,  and  which  will  not  exfoliate  or  absorb  moisture  in  quantity 
sufficient  to  destroy  its  polish.  The  ingredients  of  the  enamel 
having  been  comminuted,  are  carefully  mixed  together  and  brought 
to  a  state  of  complete  vitrifaction  in  a  reverberatory  furnace. 
Then  the  enamel  is  run  off  as  usual  into  water  to  granulate,  when 
it  is  ready  for  grinding.  In  making  an  enamel  for  wrought  or 
sheet-iron  ware,  100  lbs.  of  the  enamel  are  ground,  adding  about 
5  lbs.  of  clay,  preferably  white,  and  having  a  pronounced  soapy 
feeling,  this  clay  helping  to  give  body  to  the  enamel  and  preventing 
its  “  crazing  ”  when  it  is  finally  fixed  on  the  iron  in  the  heat  of  a 
muffle.  It  is  advisable  to  introduce,  along  with  the  enamel  and 
clay  in  the  grinding  process,  calcined  magnesia  carbonate  in  the 
proportion  of  8  ozs.  to  100  lbs.  of  the  enamel.  The  magnesia 
serves  to  make  the  enamel  coat  as  finally  applied  less  transparent, 
contributes  to  the  flecking  or  spotting  of  it  with  white,  and  thus 
in  a  measure  prevents  the  iron  base  from  imparting  to  the  enamel 
throughout  its  own  dull  and  unattractive  shade.  Prepared  as  above 
the  mixture  is  run  through  a  strainer  into  tubs,  where  it  is  allowed 
to  remain  about  one  day,  during  which  time  a  sort  of  ripening  is 


302 


TEE  METAL  WORKER’S  HANDY-BOOK. 


effected,  when  it  is  finally  prepared  as  follows :  The  mixture  being 
brought  to  about  the  consistency  of  cream  by  the  addition,  if 
necessary,  of  water,  magnesia  sulphate  is  added  until  the  mixture 
is  coagulated  and  pasty,  yet  still  capable  of  being  shaken  out  into 
a  thin  and  uniform  coat,  2  ozs.  magnesia  sulphate  being  usually 
sufficient  for  100  lbs.  of  the  mixture.  The  mixture  having  been 
finally  prepared,  the  article  is  dipped  into  it,  having  been  first 
prepared  by  the  well-known  processes  of  annealing,  pickling, 
scouring  and  washing.  For  washing,  clean  water  is  used,  the  iron 
remaining  therein  until  it  is  dipped.  Care  should  be  taken  that 
the  enamel  is  not  laid  on  too  heavily,  and  that  it  be  evenly  dis¬ 
tributed.  Having  received  a  thin  uniform  coat  by  dipping,  the 
article  is  dried,  for  if  the  enamel  coat  is  burned  while  still  damp  it 
will  crack  or  craze.  This  drying  is  accomplished  for  convenience 
and  despatch  in  an  oven  constructed  for  the  purpose,  the  range  of 
heat  in  which  varies  from  about  ioo°  to  200°  F.,  but  it  may  be 
effected  at  summer  heat  in  an  ordinary  close  room.  The  higher 
the  temperature  the  smaller  and  less  distinct  the  spots;  the  lower 
the  temperature  the  more  pronounced  the  mottling.  The  time  re¬ 
quired  depends  on  the  thickness  of  the  enamel  coat,  the  quantity 
of  moisture  present,  and  the  degree  of  heat  employed.  When 
thoroughly  dried  the  coat  is  of  a  whitish  color,  and  usually  either 
brown  or  reddish-brown  spotted  ;  and  when  burned  in  a  muffle  is  of 
grayish  color,  dark  spotted.  The  burning  process  is  effected  in  an 
ordinary  muffle  at  a  red,  cherry-red,  or  slightly  greater  heat,  the 
ordinary  time  required  being  about  4  minutes. 

Enamel for  Cast-iron  Pipes  According  to  Amtmann. — The  ground 
mass  consists  of  quartz,  34  parts;  borax,  15;  and  soda,  2.  The 
covering  mass  is  composed  of  feldspar,  34  parts;  quartz,  19; 
borax,  24;  stannic  oxide,  16;  fluorspar,  4;  soda,  9;  and  salt¬ 
petre,  3.  The  fusing  of  the  covering  mass  requires  a  strong  white 
heat  for  20  minutes,  and  the  outside  of  the  hot  finished  pipes  is 
provided  with  a  coat  of  tar. 

Glaze  for  Iron  Pipes.— To  protect  iron  pipes  buried  in  the 
ground  for  a  long  time  from  destroying  influences,  it  is  recom¬ 
mended  to  coat  them  with  a  glaze  composed  of  pulverized  crystal 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  303 


glass,  260  parts;  soda,  41  parts;  and  borax,  24  parts.  The  care¬ 
fully  mixed  ingredients  are  fused  in  a  crucible,  and,  after  cooling, 
the  mass  is  converted  into  a  very  fine  powder  by  pounding  and 
grinding.  The  pipes  to  be  coated  are  first  cleansed  by  pickling  in 
the  usual  manner,  then  washed  and  dried.  They  are  next  coated 
with  a  thin  layer  of  solution  of  gum-arabic  and  then  the  powder 
is  distributed  over  them  by  means  of  a  sieve.  To  expel  all  moisture 
the  pipes  are  next  placed  in  a  room  heated  to  about  320°  F.,  and 
finally  heated  to  a  red  heat,  at  which  the  coat  of  glaze  fuses. 
When  the  coating  is  uniform  it  adheres  very  firmly  to  the  iron  sur¬ 
face  and  resists  all  external  influences.  This  process,  called 
by  the  inventor,  Emaille  de  fer  contre-oxyde ,  may  be  recommended 
for  iron  pipes  which  are  to  possess  special  power  of  resisting  external 
influences,  but  for  general  use  it  is  perhaps  too  expensive. 

Glass  Enamel  for  Iron. — The  articles,  kitchen  utensils,  signs, 
etc.,  coated  with  this  enamel,  are  not  affected  by  atmospheric 
influences,  nor  destroyed  by  an  ordinary  fire,  and  do  not  rust. 

Intimately  mix  4  parts  of  powdered  glass,  2  of  spar,  1  of  salt¬ 
petre  and  of  a  part  of  zinc  oxide.  Fuse  them  in  a  crucible  and 
pour  into  moulds  to  cool.  For  use  the  necessary  quantity  is 
triturated  with  water.  Heat  the  iron  utensil  to  a  red  heat  in  a 
muffle  furnace  and  apply  the  enamel,  which  will  present  a  brilliant 
glassy  appearance.  To  color  the  enamel  blue,  add  cobaltic  oxide ; 
for  red,  ammonium;  for  black,  manganic  oxide;  for  yellow,  uranic 
oxide ;  for  brown,  ferric  oxide ;  for  green,  a  mixture  of  2  parts  of 
stannic  oxide  and  1  of  manganic  oxide ;  for  pure  white,  stannic 
oxide. 

Enamel  for  Copper  Cooking  Utensils. — Powder  and  mix  12  parts 
of  white  fluorspar,  12  of  unburned  gypsum  and  1  of  borax,  and 
fuse  the  mixture  in  a  crucible.  Pour  the  mass  out,  and,  when 
cold,  triturate  it  into  a  paste  with  water.  Apply  this  with  a  brush 
to  the  inside  of  the  vessel  and  place  the  latter  in  a  moderately 
warm  place  so  that  the  paste  will  dry  uniformly.  When  dry,  heat 
the  vessel  to  such  a  degree  in  a  muffle  furnace  that  the  paste  which 
has  been  applied  liquefies.  When  cold,  the  result  will  be  a  white 
opaque  enamel. 


304 


THE  METAL  WORKER’S  HANDY-BOOK. 


Colored  Enamels. — As  a  ground  mass  for  colored  enamels  the 
following  compositions  may  be  used  :  Sand,  3  parts ;  chalk,  1  ; 
calcined  borax,  3.  This  composition  is  especially  suitable  for  pale 
red,  purple  and  blue,  but  may  also  serve  for  other  delicate  colors, 
as  it  exerts  no  injurious  influences  upon  the  substances  contained  in 
the  colors.  A  composition  which,  though  it  fuses  with  difficulty, 
may  be  used  for  any  color  is  as  follows :  Quartz  meal,  60  parts ; 
alum,  30;  common  salt,  35;  red-lead,  100;  magnesia,  5.  For 
painting  on  enamel  it  is  best  to  keep  on  hand  the  various  colors  in 
the  form  of  sad-colored  vitrifiable  pigments.  For  this  purpose 
prepare  a  readily  fusible  enamel,  which,  however,  must  contain  a 
covering  body,  such  as  oxide  of  tin  or  lead,  and  add  the  coloring 
'  oxides.  After  fusing  the  mass  convert  it  into  a  coarse  powder, 
which  is  again  fused.  This  operation  is  continued  until  a  uniformly 
colored  pigment  is  obtained.  The  latter  is  then  pulverized, 
mixed  with  oil  of  lavender  and  applied  to  a  ground  mass,  con¬ 
sisting  of  pure  white  refractory  enamel.  When  the  picture  is  com¬ 
pleted  the  object  is  carefully  heated  in  the  muffle  so  that  only  the 
colored  composition  fuses.  When  this  is  the  case  the  heat  is  at 
once  moderated  to  prevent  the  colors  from  running  together.  If 
the  painting  does  not  turn  out  well  it  may  be  effaced  by  careful 
scraping  with  a  very  hard  graver  and  again  covered  by  painting 
over ;  but  it  is  very  difficult  to  execute  this  operation  in  such  a 
manner  as  not  to  injure  the  beauty  and  uniformity  of  the  paint¬ 
ing. 

Enamels  for  Goldsmiths. — These  differ  from  ordinary  enamels  in 
having  a  vivid  lustre  and  a  beautiful  color,  which  must  not  suffer  a 
change  in  remelting.  As  coloring  agents  metallic  oxides  by  them¬ 
selves  or  in  mixtures  are  used  as  follows  : 

For  blue,  oxide  of  cobalt  ;  for  rose-color  and  blue-gray,  oxide  of 
gold  ;  for  white,  oxide  of  tin  ;  for  yellow  and  brown ,  oxide  of 
uranium;  for  yellow,  red  and  brown,  oxide  of  iron  ;  for  yellow  and 
blue-green,  oxide  of  chromium ;  for  violet  and  brown,  oxide  of 
manganese. 

The  enamels  are  finely  pulverized  and  made  with  water  into  a 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING. 


305 


thin  paste.  After  having  been  applied  to  the  metal  and  dried,  they 
are  burnt  in  the  muffle,  and,  after  cooling,  polished. 

White  Enamel  for  Ornamental  Articles. — Calcine  together  and 
convert  completely  into  oxide  2  parts  of  tin  and  1  of  lead.  Mix  1 
part  of  this  oxide  mixture  with  2  parts  of  pulverized  white  crystal 
glass,  and  after  adding  a  very  small  quantity  of  saltpetre  or  pyro- 
lusite  as  a  decolorizing  agent,  fuse  in  a  small  crucible,  and  pour  the 
fused  mass  into  cold  water.  Repeat  the  fusing  twice  or  three 
times,  or  until  the  mass  is  no  longer  blistered,  but  thoroughly 
homogeneous.  It  is  then  rubbed  to  a  fine  powder,  and  may  be 
applied  either  by  itself,  or,  for  small  surfaces,  by  mixing  it  with  oil 
of  lavender  and  laying  it  on,  like  oil  paint,  with  a  brush.  For  the 
preparation  of  white  enamel  with  a  lower  fusing  point,  the  follow¬ 
ing  composition  may  be  used  :  100  parts  of  the  tin-lead  oxide,  60 
of  pure  quartz  meal,  and  25  of  common  salt.  In  place  of  pure 
quartz  meal  sand  may  be  used,  which  must,  however,  be  subjected 
to  purification,  in  order  to  yield  a  white  product.  For  this  pur¬ 
pose  calcine  100  parts  of  sand  with  25  of  common  salt.  The  iron 
contained  in  the  sand  combines  with  the  chlorine  of  the  common 
salt  to  a  combination  which  evaporates  on  heating,  and  a  fritted 
mass  sufficiently  free  from  iron  remains  behind.  The  sand  is  then 
mixed  with  25  parts  of  red-lead  and  fused.  In  this  manner  a 
fritted  mass  representing  a  lead-soda  glass  is  obtained.  To  prepare 
enamel  with  this  mass,  it  is  finely  pulverized  and  mixed  with  a  zinc 
oxide,  or  with  the  mixture  of  tin  oxide  and  lead  oxide,  by  using 
100  parts  of  oxide  to  50  of  the  frit.  The  larger  the  quantity  of  tin 
oxide  in  the  enamelling  mass  the  thinner  the  coating  may  be. 
Enamelling  masses  containing  no  tin  oxide  may  also  be  prepared, 
sodium  antimonate  being  generally  used  in  this  case.  A  composi¬ 
tion  giving  a  very  beautiful  enamel  consists  of  a  mixture  of  3  parts 
of  crystal  glass,  1  of  sodium  antimonate,  and  a  very  small  quantity 
of  saltpetre.  In  preparing  all  these  kinds  of  enamel  care  must  be 
had  in  fusing  to  prevent  the  action  of  reducing  bodies  in  the 
crucible  by  closing  the  latter  with  a  well-fitting  lid.  If  fire  gases 
penetrate  into  the  crucible,  enamelling  masses  of  inferior  quality 
are  obtained. 

20 


306 


TUB  METAL  WORKER'S  II ANDY-BOOK. 


Emaille  Cloisonnee. — The  work  known  under  this  name  is  exe¬ 
cuted  in  a  peculiar  manner,  generally  upon  copper  or  gold,  and 
gives  an  enamel  of  unlimited  durability.  The  outlines  of  the 
design  to  be  executed  in  enamel  are  chiselled  in  the  surface  of  the 
metal,  so  that  a  very  narrow  plate  of  metal  remains  standing 
between  the  boundaries  of  enamel  of  a  determined  color.  The 
place  inside  of  the  outlines  is  chiselled  out  with  a  graver,  and  the 
surfaces  remaining  standing  are  made  as  rough  as  possible,  in  order 
to  offer  a  good  hold  to  the  enamel.  For  articles  of  gold  the  out¬ 
lines  for  the  enamelling  masses  are  frequently  formed  of  thin  strips 
of  sheet  gold,  which  are  placed  upon  the  plate  and  fused  together 
^vith  it  by  heating.  In  the  cavities  prepared  in  this  manner  the 
enamelling  mass  mixed  to  a  thick  paste  with  oil  of  lavender  or  water 
is  placed,  the  application  and  fusing  of  the  mass  being  repeated 
until  the  cavities  are  entirely  filled.  Enamels  of  various  colors  can 
be  used,  each  color  being  terminated  by  the  edges  of  the  cavities, 
and  after  heating  the  articles  appear  coated  with  the  firmly  adhering 
enamel.  After  the  last  fusing  of  the  enamel  the  object  is  ground 
and  polished. 

Enamelling  Watch-dials. — Thin  sheet-iron  is  cut  into  the  desired 
shape  and  pressed,  the  edges  being  raised  to  prevent  the  enamel 
from  running  off  when  in  a  fluid  state.  The  plate  is  then  cleansed. 
The  proper  proportion  of  the  enamelling  mixture  is  as  follows, 
though  in  many  cases  and  for  special  purposes  it  may  be  slightly 
modified:  White-lead,  12  parts;  arsenic,  2^/2  ;  crystal  glass,  8 ;  salt¬ 
petre,  3;  borax,  6 ^  ;  flint,  2.  The  ground  ingredients  are  mixed, 
fused  in  a  crucible,  and  while  hot  chilled  in  cold  water,  which  ren¬ 
ders  the  mass  easily  broken.  It  is  next  crushed  to  the  fineness  of 
coarse  sand,  washed,  dried,  and  is  then  ready  for  use.  The 
cleansed  and  dried  dials  are  scattered  over,  according  to  the 
desired  thickness  of  the  coating,  with  more  or  less  of  the  powder, 
and  then  placed  in  a  muffle.  Lettering  and  figuring  may  be 
executed  in  the  usual  manner.  If  they  are,  however,  to  be  put 
upon  the  cold  enamel  they  are  printed  on  the  dial  with  soft  black 
enamel  by  transferring.  The  dial  is  then  again  placed  in  the 
muffle  to  fuse  the  enamel  of  the  lettering  and  figuring.  The  color 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  307 


of  the  enamel  may,  of  course,  be  varied  by  the  addition  of  different 
salts  and  earths,  for  instance,  by  cobalt,  peroxide  of  manganese, 
peroxide  of  iron,  etc.  ;  a  similar  variation  of  color  for  the  lettering 
and  figuring  being  also  possible. 

Emaille  Plaque-vitro-metalliquc. — The  articles  are  first  treated  in 
exactly  the  same  manner  as  given  under  “  Glaze  for  Lro?i  Pipes,” 
and  after  burning  in  of  the  enamel,  coated  again  with  a  solution  of 
gum.  Upon  this  coating  of  gum  are  then  placed  very  thin  leaves 
of  beaten  metal — copper,  gold,  silver,  platinum,  etc. — and  burnt 
in. 

Emaille-champ  Levee  is  prepared  by  stamping  thin  gold  sheets 
with  steel  dies,  filling  in  the  depressions  thus  made  with  enamel, 
and  burning  the  latter  in. 

Phosphorescent  Enamel. — Commercial  phosphorescent  paint  in 
powder  is  intimately  mixed  with  of  its  weight  of  very  finely 
pulverized  fluorspar  or  cryolite  and  of  calcium  borate.  The 
mixture  is  made  into  a  paste  with  water,  and  applied  in  a  uniform 
layer  to  the  articles  to  be  enamelled  by  means  of  a  brush.  They 
are  then  burnt  in  the  usual  manner. 

To  Secure  Enamel  and  Glass  to  Metal  by  Means  of  the  Electric 
Current. — The  enamel,  pieces  of  glass,  etc.,  arranged  upon  a  per¬ 
forated  metal  support,  are  immersed  in  a  metallic  solution  (of 
copper,  zinc,  gold,  etc.),  and  an  electric  current  is  conducted 
through  the  latter.  The  current  effects  a  separation  of  the  metal 
in  the  solution,  which  fills  up  the  spaces  between  the  enamel, 
pieces  of  glass,  etc.,  and  the  perforations  of  the  support,  whereby  a 
durable  union  with  the  metallic  support  is  effected. 

Engraving  on  Copper. — This  is  executed  by  cutting  lines  repre¬ 
senting  the  subject  on  a  copper  plate  by  means  of  a  steel  instru¬ 
ment,  called  a  graver  or  burnin,  ending  in  an  unequal-sided 
pyramidal  point.  Besides  the  graver,  the  other  instruments  used 
in  the  process  are  a  scraper,  a  burnisher,  an  oil-stone  and  a  cushion 
for  supporting  the  plate.  In  cutting  the  lines  on  the  copper  the 
graver  is  pushed  forward  in  the  direction  required,  being  held  at  a 
small  inclination  to  the  plane  of  the  copper.  The  use  of  the 
burnisher  is  to  soften  down  the  lines  that  are  cut  too  deeply  and 


308 


THE  METAL  WORKER’S  HANDY-BOOK. 


for  burnishing  out  scratches  in  the  copper ;  it  is  about  3  inches 
long.  The  scraper,  like  the  burnisher,  is  of  steel,  with  three  sharp 
edges  to  it ;  it  is  about  6  inches  long,  tapering  towards  the  end. 
Its  use  is  to  scrape  off  the  burr  raised  by  the  action  of  the  graver. 
To  show  the  appearance  of  the  work  during  its  progress,  and  to 
polish  off  the  burr,  engravers  use  a  roll  of  woollen  cloth  or  felt, 
called  a  rubber,  which  is  used  with  a  little  olive  oil.  The  cushion, 
which  is  a  leather  bag  about  9  inches  in  diameter  filled  with  sand, 
for  laying  the  plate  upon,  is  now  rarely  used  except  by  writing 
engravers.  For  architectural  subjects  or  for  skies,  where  a  series 
of  parallel  lines  is  wanted,  a  ruling-machine  is  used,  which  is  very 
accurate.  This  is  made  to  act  on  an  etching  ground  by  a  point  or 
knife  connected  with  the  apparatus,  the  lines  thus  made  being  bit¬ 
in  with  nitric  acid  in  the  ordinary  way. 

The  copper  plate  must  be  perfectly  polished,  very  level,  and  free 
from  any  imperfection  ;  to  this  must  be  transferred  an  exact  copy 
of  the  outlines  of  the  drawing.  To  do  this  the  plate  is  uniformly 
heated  in  an  oven  or  otherwise  till  it  is  sufficiently  hot  to  melt 
white  wax,  a  piece  of  which  is  then  rubbed  over  it  and  allowed  to 
spread  so  as  to  form  a  thin  coat  over  the  whole  surface,  after  which 
it  is  left  in  a  horizontal  position  till  the  wax  and  plate  are  cold.  A 
tracing  of  the  original  design  having  been  taken  with  a  black  lead- 
pencil  on  a  piece  of  thin  tracing  paper,  it  is  spread  over  the  face 
of  the  prepared  plate,  with  the  lead  lines  downwards,  and  being 
secured  from  slipping,  a  strong  pressure  is  applied,  by  which 
operation  the  lead  lines  are  nearly  removed  from  the  paper,  being 
transferred  to  the  white  wax  on  the  plate.  The  pencil  marks  on 
the  wax  are  now  traced  with  a  fine  steel  point  so  as  just  to  touch 
the  copper;  the  wax  is  then  melted  off,  and  a  perfect  outline  will 
be  found  on  the  copper,  on  which  the  engraver  proceeds  to  execute 
his  work. 

Engraving  on  Silver  or  Gold. — I.  The  engraving  is  first  exposed 
to  the  vapor  of  iodine,  which  deposits  upon  the  black  parts  only. 
The  iodized  engraving  is  then  applied  with  slight  pressure  to  a 
polished  plate  of  silver  or  silvered  copper.  The  black  parts  of  the 
engraving,  which  have  taken  up  the  iodine,  part  with  it  to  the 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCIIING.  309 


silver  which  is  converted  into  an  iodide  at  those  parts  opposite  to 
the  black  parts  of  the  design.  The  plate  is  then  put  in  com¬ 
munication  with  the  negative  pole  of  a  small  battery  and  immersed 
in  a  saturated  solution  of  sulphate  of  copper,  connected  with  the 
positive  pole  by  means  of  a  rod  of  platinum.  Copper  will  be 
deposited  on  the  non-iodized  parts  corresponding  to  the  white 
parts  of  the  engraving,  of  which  a  perfect  representation  will  thus 
be  obtained ;  the  copper  representing  the  white  parts  and  the 
iodized  silver  the  black  parts.  The  plate  must  be  allowed  to  re¬ 
main  in  the  bath  for  only  a  very  short  time,  for  if  left  too  long, 
the  whole  plate  would  become  covered  with  copper.  The  plate, 
after  having  received  the  deposit  of  copper,  must  be  carefully 
washed,  and  afterwards  immersed  in  a  solution  of  sodium  hyposul¬ 
phite  to  dissolve  the  iodide  of  silver,  which  represents  the 
black  parts ;  it  is  then  thoroughly  washed  in  distilled  water  and 
dried. 

II.  Heat  a  silver  plate,  previously  coated  with  copper,  to  a 
temperature  sufficient  to  oxidize  the  surface  on  the  copper,  which 
successively  assumes  different  tints,  the  heating  being  interrupted 
when  a  dark  brown-color  is  obtained.  It  is  then  allowed  to  cool, 
and  the  exposed  silver  is  amalgamated,  the  plate  being  slightly 
heated  to  facilitate  the  operation.  As  the  mercury  will  not  com¬ 
bine  with  the  oxide  of  copper,  a  design  is  produced  of  which  the 
amalgamated  parts  represent  the  black,  and  the  parts  of  the  plate 
covered  with  oxide  of  copper  the  white  ones.  The  amalgamation 
being  complete,  the  plate  is  to  be  covered  with  three  or  four  thick¬ 
nesses  of  gold-leaf,  and  the  mercury  is  evaporated  by  heat,  the 
gold  adhering  only  to  the  black  parts.  The  superfluous  gold  must 
then  be  cleaned  off  with  the  scratch-brush ;  after  which  the  oxide 
of  copper  is  dissolved  by  a  solution  of  nitrate  of  silver,  and  the  silver 
and  copper  underneath  are  attacked  with  dilute  nitric  acid.  Those 
parts  of  the  design  which  are  protected  by  the  gold,  not  being 
attacked  by  the  acid,  correspond  to  the  black  parts  of  the  plate ; 
the  other  parts  corresponding  to  the  white  parts  of  the  engraving 
may  be  sunk  to  any  required  depth.  When  this  operation  is  com- 


310 


THE  METAL  WORKER’S  II ANDY-BOOK. 


pieted  the  plate  is  finished  and  may  be  printed  from  in  the  ordi¬ 
nary  method  of  printing  from  wood-cuts. 

To  Engrave  Aluminium. — One  of  the  many  interesting  pecu¬ 
liarities  of  aluminium  is  its  resistance  to  the  direct  action  of  the 
graver;  the  tool  slips  off  like  from  a  hard  surface  of  glass.  How¬ 
ever,  by  using  a  varnish  of  4  parts  of  oil  of  turpentine  and  1  of  stearin, 
mixed  with  1  of  rum,  the  graver  penetrates  the  aluminium  like 
pure  copper. 

Soft  Wax  for  Engravers. — Melt  together  tallow,  1  part,  and  yel¬ 
low  wax,  2  parts  ;  or,  olive  oil,  1  part,  and  yellow  wax,  5  parts  ; 
or,  turpentine,  1  part,  and  yellow  wax,  4  parts ;  or,  yellow  wax, 
5  parts,  and  Venetian  turpentine,  3  parts. 

Wax-mass  for  Copper  Engravers. — As  an  excellent  coating  for 
copper  plates  which  are  to  be  engraved,  the  following  mixtures  can 
be  especially  recommended  :  For  work  in  winter  :  Yellow  wax, 
40  parts ;  mastic,  30;  asphalt,  15.  For  work  in  summer Yellow 
wax,  120  parts;  mastic,  30;  asphalt,  60;  amber,  30.  Melt  the 
asphalt  and  the  wax,  each  by  itself,  and,  after  allowing  the  mastic 
to  dissolve  in  the  wax,  mix  both  substances  together  with  constant 
stirring.  For  use  the  mass  as  well  as  the  copper  plate  must  be 
heated,  the  latter  for  the  purpose  of  making  the  ground  adhere  more 
firmly. 

Etching-ground. — I.  White  wax,  1  part;  mastic,  1  part;  asphalt, 
*4  part.  Pulverize  the  mastic  and  asphalt,  each  by  itself,  melt  the 
wax  in  an  earthen  pot  over  a  fire,  and  when  very  hot  add,  with 
constant  stirring,  first  the  mastic  powder  and  then  the  asphalt  pow¬ 
der.  Continue  the  stirring  until  the  asphalt  is  completely  melted, 
then  remove  the  pot  from  the  fire,  allow  the  mixture  to  cool,  and 
pour  it  into  clean  warm  water.  While  in  the  water  knead  the  mix¬ 
ture  with  the  hand,  and  finally  form  it  into  small  cylinders  or  balls, 
which  are  kept  for  use  wrapped  in  taffeta. 

II.  Mastic,  2  parts;  asphalt,  1. 

III.  White  wax,  3  parts ;  asphalt,  4 ;  black  pitch,  1  ;  colophony,  1 . 
First  melt  the  wax  and  pitch,  next  add  the  colophony  and 
asphalt,  and  then  boil  until  a  sample  after  cooling  readily  breaks 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  311 


on  bending.  In  melting,  a  carbonizing  heat  should  be  strictly 
avoided. 

Callot's  Etching-ground  consists  of  pure  linseed-oil  varnish,  which 
is  heated  in  an  earthen  pot,  and  mixed  with  an  equal  weight  of 
powdered  mastic,  the  mass  being  constantly  stirred.  When  inti¬ 
mately  melted  together  the  mixture  is  filtered  through  fine  linen 
into  a  bottle.  For  use  the  mixture  is  applied  to  the  heated  plate 
by  means  of  a  brush,  and  after  smoothing  the  coat  with  a  tuft  of 
cotton  it  is  dried  by  being  held  over  the  heated  plate,  until  the 
varnish  ceases  to  smoke. 

Etching  on  Copper. — For  coating  the  plates  ordinary  etching- 
ground  is  used,  while  pure  nitric  acid  with  y$  water,  poured  j4 
centimetre  deep  upon  the  plates,  serves  as  corroding  solution. 
Callot  and  Piranesi's  corroding  solution  acts,  however,  with  greater 
uniformity.  It  is  prepared  from  wine  vinegar,  8  parts ;  verdigris, 
4;  common  salt,  4;  alum,  1  ;  and  water,  16.  A  corroding  solu¬ 
tion  which  can  be  highly  recommended  is  prepared  as  follows  : 
Dilute  10  parts  of  fuming  nitric  acid  with  70  of  water,  and  add  a 
boiling  solution  of  2  parts  of  potassium  chlorate  in  20  of  water. 
For  etching  slighter  portions,  the  solution  may  be  further  diluted 
with  100  or  200  parts  of  water.  Deeper  places  are  produced  by 
allowing  the  corroding  solution  to  act  for  a  longer  time,  or  by  the 
addition  of  fluid  of  greater  strength. 

Etching  on  Brass  and  Silver  is  executed  in  the  same  manner  as 
on  copper. 

Etching  on  Steel. — Fine  lines  are  produced  in  1  to  2  minutes, 
and  the  strongest  lines  in  15  minutes,  by  a  corroding  solution 
composed  of  4  parts  of  pyroligneous  or  ordinary  acetic  acid,  to 
which  is  subsequently  added  1  part  of  rectified  alcohol.  A  mix¬ 
ture  of  3  ozs.  of  warm  water,  4  grains  of  tartaric  acid,  and  4  drops 
of  nitric  or  sulphuric  acid  may  be  used  for  very  soft  steel.  Many 
metallic  solutions  diluted  with  the  necessary  amount  of  water  may 
also  serve  as  corroding  solution,  they  having  the  advantage  of  no 
bubbles  being  formed.  Among  others  may  be  mentioned  the  solu¬ 
tions  of  stannates,  bismuth  nitrate  and  cupric  nitrate,  though  with 
the  use  of  the  latter  the  precipitating  copper  exerts  an  injurious 


312 


TITE  METAL  WORKER’S  nANDY-BOOK. 


influence.  For  fine  lines  Humphry' s  mixture  is  used  ;  it  is  prepared 
by  dissolving  y£  oz.  each  of  corrosive  sublimate  and  alum  in  i 
quart  of  hot  water.  After  cooling  the  solution  is  applied  with  a 
fine  brush.  The  fine  lines  are  produced  in  about  3  minutes.  The 
corroding  solution  having  acted  sufficiently  it  is  poured  off  and  the 
plate  washed  with  alcohol  diluted  with  4  parts  of  water.  To  pre¬ 
vent  any  further  action  of  remaining  traces  of  corroding  solution, 
the  lines  are  filled,  by  means  of  a  brush,  with  oil  of  turpentine 
containing  some  asphalt  in  solution,  and  the  plate  is  protected  from 
rust  by  a  coat  of  caoutchouc  varnish  or  of  mutton-suet. 

Etching  Names  on  Steel  and  Glass. — With  equal  quantities  of 
cupric  sulphate  (blue  vitriol),  sodium  chloride  (common  salt),  well 
powdered  and  mixed  together,  names  or  other  marks  can  be  etched 
on  steel  surfaces.  The  wax  process  must  be  used,  although  soap 
will  answer,  or  any  other  substance  not  acted  upon  by  acids. 
Spread  the  beeswax  or  soap  in  a  thin,  even  coating  over  the  article 
to  be  etched,  and  with  a  sharp-pointed  awl  write  or  draw  the 
design  upon  the  wax-covered  surface.  Every  line  must  be  cut 
cleanly,  and  every  particle  of  the  coating  removed,  otherwise  a 
break  will  appear  in  the  etched  line.  When  the  drawing  has  been 
made  satisfactory,  put  a  “tinker’s  dam”  around  the  wax-covered 
spot ;  this  is  done  by  rolling  out  a  piece  of  putty  into  a  long,  thin 
roll,  bending  it  around  the  wax-covered  spot  and  pressing  it  lightly 
down,  thus  making  a  little  reservoir  to  hold  the  acid  or  other  cor¬ 
roding  substance.  Mix  up  the  salt  and  sulphate  of  copper,  fill 
inside  the  dam,  and  moisten  with  water  to  hasten  their  action. 
When  satisfied  that  the  etching  is  deep  enough,  or  tired  of  waiting 
for  it  to  work,  wash  off  the  corroding  mixture  and  scrape  off  the 
wax,  or  dissolve  it  away  with  turpentine,  alcohol,  or  naphtha.  If 
the  etching  is  not  deep  enough,  an  ink  roller,  such  as  is  used  on 
printing  presses,  may  be  passed  over  the  surface  and  a  coating  of 
ink  put  on.  This  will  prevent  any  acid  action  upon  the  surface 
thus  protected,  and  the  corroding  solution  may  be  reapplied  until 
the  etching  is  sufficiently  deep.  If  successive  etchings  are  neces¬ 
sary,  the  plate  should  be  rinsed  and  warmed  after  each  removal  of 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  313 


the  corroding  solution,  and  more  ink  applied  before  another  lot 
of  fresh  corroder  is  put  to  work. 

In  regular  work,  where  large  numbers  of  zinc  etchings  are  made, 
dragon’s  blood  is  used  to  protect  the  surface  instead  of  printer’s 
ink,  but  for  occasional  work  ink  is  good  enough.  Nitric  and  sul¬ 
phuric  acids  may  be  used  for  etching,  and  the  effect  of  the  compo¬ 
sition  described  above  depends  upon  the  chlorine  and  sulphuric 
acid  set  free  by  the  combination  of  the  two  salts. 

Etching  on  glass  may  be  done  as  easily  as  etching  upon  steel  or 
other  metals.  To  do  this  exactly  the  same  preparations  are  made, 
then  a  mixture  of  sulphuric  acid  and  a  powdered  fluorspar  is  spread 
upon  the  surface  to  be  etched.  Another  and  cleaner  way,  although 
it  takes  longer,  is  to  put  the  acid  and  powdered  spar  in  a  shallow 
lead  dish  and  invert  over  it  the  article  to  be  etched.  The  subject 
thus  serving  as  a  cover  to  the  acid  dish,  it  is  exposed  to  the  fumes 
which  arise  and  which  are  almost  as  corrosive  as  the  mixture  itself. 
Etching  is  always  unsatisfactory  unless  the  wax  is  evenly  spread, 
cleanly  cut  out,  and  everything  very  neatly  done. 

Etching  on  Zinc. — Dissolve  2  parts  of  crystallized  cupric  sul¬ 
phate  (blue  vitriol)  and  3  of  cupric  chloride  in  64  of  distilled 
water  and  add  to  the  solution  8  parts  of  hydrochloric  acid  of  1.1 
specific  gravity.  This  fluid  has  a  slightly  bluish  color  and  sheet- 
zinc  previously  scoured  bright  with  dilute  hydrochloric  acid  and 
sand  instantly  acquires,  on  being  dipped  into  it,  a  very  deep  velvety 
black  color.  By  instantly  withdrawing  the  sheet-zinc  thus  treated 
from  the  fluid  and  immediately  rinsing  it  off  in  abundance  of  clean 
water  and  then  drying,  the  black  coating  adheres  very  firmly,  so 
that  it  is  probable  that  this  mode  of  etching  may  answer  in  many 
cases  as  a  sort  of  paint,  especially  for  zinc  intended  for  roofing. 
For  etching  zinc  in  relief  it  is  only  necessary  to  draw  the  lines,  let¬ 
ters,  etc.,  upon  the  zinc  with  the  above-described  fluid  and,  after 
drying,  place  the  zinc  for  1  to  3  hours,  according  to  requirement, 
in  dilute  nitric  acid  (1  part  acid  to  8  water).  By  this  means  the 
zinc  is  eaten  away  while  the  lines,  letters,  etc.,  remain  in  relief. 

Etching  Solution  for  Brass. — Prepare  a  mixture  of  8  parts  of 
nitric  acid  of  specific  gravity  1.40  and  80  parts  of  water;  further- 


314 


THE  METAL  WORKER’S  HANDY-ROOK. 


more  dissolve  3  parts  of  potassium  chlorate  in  50  of  water.  The 
two  fluids  are  mixed  and  used  for  etching.  Ordinary  etching 
ground  is  used  for  covering. 

Glyphogene  or  Etching  Fluid  for  Steel. — This  etching  fluid  con¬ 
sists  of  the  preparatory  corroding  solution,  the  rinsing  water  and 
the  actual  corroding  solution.  The  preparatory  corroding  solution 
consists  of  water,  95  parts;  chemically  pure  nitric  acid,  5  parts, 
and  some  spirits  of  wine,  and  is  allowed  to  act  for  a  few  minutes 
only.  The  articles  treated  with  the  preparatory  corroding 
solution  are  then  rinsed  off  with  the  rinsing  water,  consisting  of 
distilled  water  containing  1/3  of  its  volume  of  spirits  of  wine,  and 
quickly  dried.  The  actual  corroding  solution  is  composed  of  dis¬ 
tilled  water,  30  parts;  spirits  of  wine,  15;  chemically  pure  nitric 
acid,  6,  and  crystallized  nitrate  of  silver,  y j.  A  layer  0.59  inch 
deep  is  poured  upon  the  plate. 

Etching  without  Etching-ground. — A  method  of  employing  the 
galvanic  precipitation  of  metals  for  the  production  of  ornamenta¬ 
tion  either  sunk  or  in  relief  is  given  by  Millvard  and  executed  as 
follows  :  In  order  to  produce  sunk  figures  or  drawings  the  latter  are 
first  laid  or  printed  upon  the  metallic  surface.  A  very  thin  layer 
of  gold,  silver  or  copper  is  then  galvanically  precipitated  in  the 
ordinary  manner.  The  precipitated  metal  deposits  itself  upon  all 
parts  of  the  surface  except  those  covered  by  the  drawing.  The 
surface  of  the  metal  is  now  cleansed  from  the  material  with  which 
the  drawing  has  been  executed  and  is  then  connected  with  the 
negative  pole  of  a  galvanic  battery,  whereby  a  solution  is  used 
which  acts  only  upon  the  metal  of  the  original  plate,  so  that  all  the 
places  previously  covered  by  the  ground  are  dissolved  or  sunk.  In¬ 
stead  of  using  a  galvanic  battery  the  metallic  surface  may  be  simply 
dipped  into  a  solution  of  an  acid  which  only  attacks  the  bare  places 
of  the  surface,  but  not  the  metal  deposited  upon  it.  The  sunk 
drawing  may  on  various  places  be  provided  with  relief  lines  cross¬ 
ing  each  other,  so  that  it  acquires  the  appearance  of  cross-hatching. 
This  is  effected  by  drawing  such  lines  with  a  brush  dipped  in  var¬ 
nish  before  the  plate,  after  being  cleansed  from  the  protecting 
cover,  is  acted  upon  by  the  galvanic  battery  or  the  above-mentioned 


DECORATING,  ENAMELLING,  ENGRAVING,  ETCHING.  315 


chemical  agents.  Another  method  of  producing  sunk  drawings  is 
as  follows:  The  entire  surface  is  first  covered  with  a  metallic  layer 
in  the  above-described  manner.  The  whole  is  then  coated  with  a 
varnish  and  after  executing  the  drawing  in  the  varnish  the  surface 
is  exposed  to  the  action  of  the  negative  pole  of  a  galvanic  battery 
or  dipped  into  a  suitable  solution  of  an  acid  salt,  whereby  the  1 
metal,  exposed  by  cutting  through  the  varnish,  is  dissolved  and  re¬ 
moved,  thus  producing  a  sunk  drawing. 

Figures  in  Relief  are  Produced  as  follows :  A  coating  of  any 
kind  of  metal  is  first  deposited  in  the  above-mentioned  manner 
upon  the  surface  to  be  ornamented.  The  figure  desired  in  relief  is 
then  drawn  or  printed  upon  the  deposited  metal.  The  plate  is  then 
connected  with  the  negative  pole  of  a  galvanic  battery  or  dipped 
into  a  solution  of  an  acid  salt,  whereby  all  the  bare  portions  of  the 
deposited  metal  are  dissolved  and  removed,  while  the  lines  of  the 
intended  figure  remain  standing  out  in  relief.  According  to  another 
method  the  entire  surface  is  coated  with  varnish  and  the  drawing 
scratched  into  the  latter.  The  places  thus  bared  from  varnish 
receive  a  galvanoplastic  coating  of  any  kind  of  metal,  after  which 
all  the  remaining  varnish  is  removed  from  the  plate.  The  latter  is 
then  exposed  to  the  action  of  the  negative  pole  of  a  galvanic  bat¬ 
tery  or  treated  with  a  fluid  which  attacks  the  metal  of  the  original 
surface,  but  not  the  deposited  metal. 

For  copper  printing  plates  it  is  especially  recommended  to  cut 
with  a  fine,  hard  needle  or  a  diamond  through  the  layer  of  gold  on 
the  places  which  are  to  be  etched  and  then  to  etch  with  ferric 
chloride.  The  lines  may  be  considerably  finer  as  when  the  plate  is 
covered  with  an  etching  ground,  since  the  layer  of  gold  can  be  cut 
through  very  sharp  and  does  not  peal  off.  By  giving  the  copper 
plate  a  thin  coat  of  iron  and  scratching  in  the  drawing,  the  latter 
can  be  etched  with  argentammonium  sulphate  without  attacking 
the  iron  coating.  According  to  Prof.  Husnik,  a  solution  of  cor¬ 
rosive  sublimate  is  compounded  with  a  concentrated  solution  of 
ammonium  nitrate  and  sufficient  caustic  ammonia  added  to  re¬ 
dissolve  the  precipitate  at  first  formed.  This  corroding  substance 
also  exerts  no  etching  effect  upon  iron.  Copper  and  brass  plates 


316 


THE  METAL  WORKER’S  ITANDY-BOOK. 


treated  in  this  manner  show  clear  drawings  of  the  amalgam  which 
has  been  formed.  By  dissolving  the  iron  and  treating  the  plates 
with  a  suitable  coloring  matter,  dark  drawings  upon  a  yellow  or 
copper-colored  ground  are  obtained.  By  applying  to  etched  copper 
plates,  before  dissolving  the  iron  coating,  silver  or  gold  amalgam, 
drawings  in  gold  or  silver  are  obtained  by  the  subsequent  removal 
of  the  iron  coating  and  heating  the  plate  in  the  open  air  so  that  the 
mercury  oxidizes. 

Metallography  ( Method  for  Producing  Drawings  of  all  Kinds  in 
Relief  upon  Metal )  According  to  Zach. — The  surface  of  a  zinc  or 
steel  plate  is  finally  ground  and  polished,  then  covered  with  a 
ground  consisting  of  white  wax,  2  parts;  mastic,  2;  asphalt,  1; 
and  colophony,  ]/2,  and  smoked  with  a  wax-torch  until  it  has  a 
lustre.  Upon  this  ground  the  drawing  is  then  executed  with  a 
graver.  The  plate  is  then  surrounded  with  a  rim  of  wax  and 
etched  15  to  20  minutes  with  dilute  nitric  acid.  It  is  then  washed 
with  water,  and,  after  covering  the  fine  lines,  if  necessary,  with 
asphalt  dissolved  in  oil  of  turpentine,  etching  is  continued  for  15 
to  20  minutes  more.  The  ground  is  then  dissolved  with  oil  of 
turpentine  and  the  plate  cleansed.  In  this  manner  a  sunk  drawing 
is  obtained,  which,  however,  must  have  such  a  depth  that  the  cast¬ 
ings  to  be  made  from  it  afterwards  appear  sufficiently  in  relief  to 
allow  of  their  being  printed  from,  in  a  printing-press.  To  obtain 
from  this  matrix  a  patrice,  i.  <?.,  a  drawing  in  relief  suitable  for 
printing,  a  readily  fusible  metal  consisting  of  bismuth,  7  parts  ; 
lead,  4  ;  and  tin,  4,  is  melted.  The  plate  with  the  deeply  etched 
drawing  is  placed  in  a  heated  mould  and  the  alloy  poured  over 
it  vertically.  The  drawing  lies  afterwards  in  relief  upon  the  cast¬ 
ing  without  injury  having  been  done  to  the  original. 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


317 


XI. 

ELECTRO-PLATING,  BRASSING,  COPPERING,  GALVAN¬ 
IZING,  GILDING,  NICKELLING,  SILVERING,  TIN¬ 
NING,  ETC. 

[For  Electro-plating,  etc.,  of  Wire,  see  that  head.] 

In  all  branches  of  the  electro-deposition  of  one  metal  upon  another 
several  preliminary  conditions  have  to  be  complied  with  in  order 
that  the  deposition  may  take  place  uniformly  and  adhere  firmly. 
The  articles  must  be  absolutely  free  from  grease,  and,  furthermore, 
their  surfaces  must  be  purely  metallic.  This  is  effected  by 
mechanical  treatment  in  conjunction  with  chemical  cleaning. 
The  mechanical  treatment  varies  according  to  the  condition 
of  the  surfaces  of  the  articles  and  the  demands  made  on  the 
galvanic  deposition.  Rough  castings  to  be  galvanically  coated 
must  first  be  thoroughly  scratch-brushed  with  pumice-stone,  except 
where,  as  in  the  case  of  copper  and  its  alloys,  dipping  is  substituted 
for  this  process.  When  the  rough  surface  of  a  casting  is  coated 
with  another  metal  the  deposition  shows  the  same  roughness  as  the 
base ;  hence  the  articles  must  be  ground  or  polished  in  order  to 
obtain  depositions  with  lustrous  surfaces.  Grinding  is  almost 
exclusively  effected  upon  wooden  disks  covered  with  leather; 
emery  of  various  degrees  of  fineness  is  glued  upon  the  leather,  and, 
during  the  grinding,  a  mixture  of  emery  and  tallow  or  oil  is  from 
time  to  time  applied  to  the  articles.  When  grinding  is  finished  the 
articles  are  brushed  upon  circular  brush-disks  of  bristles  or  fibres  to 
remove  the  last  fine  scratches  ;  the  direction  of  brushing  is  at  a  right- 
angle  to  the  direction  of  the  last  grinding,  and  the  brushes  are  also 
fed  with  a  mixture  of  tallow  and  emery.  Only  articles  of  iron  and 
steel  are,  as  a  rule,  ground,  while  the  softer  metals,  copper,  zinc, 
etc.,  are  simply  brushed  and  then  polished.  Polishing  is  effected 
by  holding  the  articles  against  rapidly  revolving  disks  of  cloth  or 
felt,  which  are  secured  to  the  shaft  of  the  polishing  machine. 
According  to  the  fineness  of  the  polishing  desired,  the  polishing 


318 


THE  METAL  WORKER’S  HANDY-BOOK. 


disks  are  fed  with  various  polishing  agents,  a  mixture  of  Vienna 
lime  and  colcothar  being  mostly  used.  Grinding  disks  should 
make  from  1,200  to  1,600  revolutions  per  minute,  and  polishing 
disks  from  2,000  to  2,400  revolutions. 

The  depositions  are  polished  upon  similar  disks  of  felt  or  cloth ; 
silver  and  gold  depositions,  however,  are  burnished  with  the  bur¬ 
nisher  and  burnishing-stone. 

Many  depositions  have  to  be  scratch-brushed  during  the  galvanic 
operation  in  order  to  get  them  dense  and  thick.  This  is  done 
with  fine  brass-wire  brushes,  but  for  white  and  hard  metal  fine  steel- 
wire  brushes  are  used.  Scratch-brushing  is  never  done  dry,  water, 
decoction  of  soap-root,  beer  yeast,  etc.,  being  used  in  connection 
with  it. 

The  chemical  cleaning  consists  in  the  removal  of  grease  and  dirt 
and  of  non-metallic  layers  upon  the  surface  (scales,  rust,  etc/). 

Freeing  from  Grease  is  effected  by  boiling  the  articles  in  caustic 
lyes  (soda  or  potash  lye),  which  should  be  followed  by  brushing  or 
rubbing  with  pulverized  freshly-burnt  lime  free  from  sand.  Articles 
which  will  not  stand  heating  are  freed  from  grease  with  benzine. 

Dipping. — The  choice  of  the  fluids  for  the  removal  of  non-metal¬ 
lic  layers  depends  on  the  nature  of  the  metals  to  be  dipped.  Iron 
and  steel  are  generally  dipped  in  dilute  sulphuric  acid,  1  part  by 
weight  of  sulphuric  acid  of  66°  Be.  to  15  to  20  water;  hydro¬ 
chloric  acid  may  be  substituted  for  the  sulphuric  acid. 

Copper,  brass,  tombac  and  bronze  are  made  bright  by  dipping 
in  compound  acids.  The  operation  is  as  follows :  The  articles  are 
first  dipped  in  dilute  sulphuric  acid  to  remove  tarnish,  and  then  in 
a  mixture  of  100  parts  by  weight  of  nitric  acid  of  36°  Be.,  50  of 
sulphuric  acid  of  66°  Be.,  x  of  soot  and  1  of  common  salt.  As 
soon  as  the  articles  show  a  bright  appearance  they  are  quickly 
rinsed  in  a  large  quantity  of  water  which  must  be  frequently 
changed. 

When  copper  alloys  are  not  to  be  further  worked  after  dipping, 
it  is  generally  desirable  that  they  come  from  the  pickle  with  a  cer¬ 
tain  lustre.  To  attain  this  the  dipping  is  executed  in  two  opera¬ 
tions,  the  articles  being  first  made  bright  in  a  preliminary  pickle 


ELECTROPLATING,  BRASSING,  COPPERING,  ETC. 


319 


and  then  dipped  into  another  pickle  to  give  them  lustre.  The  pre¬ 
liminary  pickle  consists  of  nitric  acid  of  36°  Be.,  200  parts  by 
weight;  common  salt,  1  ;  soot,  x. 

The  pickle  for  bright  lustre  is  composed  of  nitric  acid  of  40° 
Be.,  75  parts  by  weight ;  sulphuric  acid  of  66°  Be.,  100,  and  com¬ 
mon  salt,  1.  The  articles  having  been  made  bright  in  the  pre¬ 
liminary  pickle,  are  rinsed  off  in  a  large  quantity  of  water,  then  drawn 
through  hot  water  so  that  they  dry  quickly,  and,  when  dry,  dipped 
into  the  pickle  for  a  bright  lustre  ;  drying  is  absolutely  necessary, 
the  lustre  obtained  being  the  more  beautiful  the  freer  the  pickle  is 
from  water. 

For  a  dead  lustre  the  brass  is  dipped  in  a  mixture  of  3  parts  of 
nitric  acid  containing  1  part  of  zinc  in  solution,  with  8  parts  of 
pure  strong  nitric  acid  and  8  parts  of  boiling  sulphuric  acid.  The 
strong  effervescence  which  first  takes  place  soon  ceases  and  the 
brass  when  taken  out  presents  a  dead  brown  or  gray  appearance. 
It  acquires  lustre  by  being  drawn  through  strong  nitric  acid. 
The  following  mixture  is  also  recommended  :  Nitric  acid  of  36° 
Be.,  200  parts;  sulphuric  acid,  100  ;  common  salt,  x  ;  sulphate  of 
zinc,  1  to  5.  This  mixture  is  used  cold. 

The  following  mixture  is  suitable  for  the  production  of  a  dull- 
trained  surface  upon  brass :  Mix  1  volume  of  saturated  solution  of 
bichromate  of  potash  and  2  of  the  strongest  hydrochloric  acid  ; 
place  the  articles  in  this  mixture  for  a  few  hours,  then  drain  them 
through  the  above-mentioned  pickle  for  bright  lustre,  and  finally 
rinse  them  in  much  water. 

German  Silver  is  first  dipped  in  a  mixture  of  nitric  acid,  1  part, 
and  water,  10  parts,  and  then  in  a  mixture  of  nitric  acid  and  sul¬ 
phuric  acid  each  x  part. 

Silver  is  dipped  in  dilute  sulphuric  acid,  zinc  also  in  dilute  sul¬ 
phuric  acid  or  in  hydrochloric  acid,  and  tin  in  hydrochloric  acid. 

In  dipping  with  acids  injurious  fumes  are  produced,  so  that  it  is 
prudent  to  operate  in  the  open  air  or  under  a  good  chimney-hood 
with  a  movable  glass  sash. 

Articles  which  are  soldered  with  soft  solder,  or  contain  iron,  be- 


320 


THE  METAL  WORKER’S  HANDY-BOOK. 


come  black  in  nitric  acid,  and  hence  such  places  must  be  made 
bright  again  with  the  scratch-brush. 

The  articles  having  been  dipped  and  freed  from  grease  are  ex¬ 
amined  as  to  whether  they  are  entirely  free  from  grease  by  im¬ 
mersing  them  in  water ;  when  entirely  free  from  grease  they 
become  uniformly  wet.  If,  however,  lines  and  spots  appear,  the 
articles  are  not  thoroughly  clean  and  must  be  again  boiled  in 
caustic  lye,  or,  still  better,  brushed  with  a  mixture  of  2  parts  whit¬ 
ing  and  1  part  freshly-slaked  lime  stirred  with  water  to  a  thick 
paste.  A  scarcely  perceptible  tarnish  (a  layer  of  oxide)  being 
readily  formed  upon  articles  freed  from  grease  by  dipiping,  it  is 
recommended  to  draw  them,  shortly  before  suspending  them  in  the 
baths,  through  a  solution  which  dissolves  the  tarnish.  For  iron 
such  solution  consists  of  dilute  sulphuric  acid  (1  acid  to  25  water), 
and  for  copper,  brass,  tombac,  bronze  and  German  silver  of  a 
solution  of  cyanide  of  potassium  (1  part  of  60  per  cent,  cyanide 
of  potassium  to  20  of  water).  The  articles  are  then  thoroughly 
rinsed  and  without  delay  brought  into  the  bath. 

The  water  used  for  the  preparation  of  the  galvanic  baths  should 
be  as  pure  as  possible,  distilled  or  filtered  rain-water  being  best  for 
the  purpose.  Care  should  be  taken  to  use  pure  chemicals,  as  the 
bad  results  from  baths  composed  of  unsuitable  materials  are  fre¬ 
quently  due  to  impure  chemicals.  Moreover,  the  baths  must  not 
be  too  poor  in  metal  nor  too  concentrated  ;  in  the  first  case  the 
depositions  form  too  slowly  and  in  the  latter  the  salts  separate 
in  crystals  enveloping  the  anodes  and  interrupting  thereby  the  con¬ 
duction  of  the  current,  while  by  the  separation  of  small  crystals 
upon  the  articles  holes  may  readily  be  formed  in  the  deposition. 
The  temperature  of  baths  which  work  cold  should  not  be  below 
590  F.,  a  temperature  of  64.5°  to  68°  F.  being  best.  Dust  must 
be  kept  away  from  the  baths  as  much  as  possible,  as  by  depositing 
upon’ the  articles  it  might  disturb  the  coherence  of  the  deposition  ; 
should  a  layer  of  dust  be  observed  upon  the  baths  they  must  be 
filtered  or  the  dust  removed  by  drawing  a  broad  strip  of  blotting- 
paper  over  the  surface. 

There  are  two  kinds  of  batteries  used  for  electro-deposition : 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


321 


those  which  act  under  the  action  of  physical  agents,  but  these,  on 
account  of  their  feeble  intensity,  are  rarely  used ;  others  act  under 
the  influence  of  chemical  reactions,  of  decompositions  and  recom¬ 
positions,  or  of  greater  or  less  affinities.  The  varieties  of  these 
instruments  are,  at  the  present  time,  very  numerous.  But  the  best 
battery  is  that  which,  under  the  smallest  volume,  is  the  most  ener¬ 
getic,  constant,  regular  and  economical. 

When  dynamo-electric  machines  are  not  used,  Bunsen’s  battery 
is  the  most  suitable  for  the  execution  of  galvanic  depositions. 
Each  element  is  composed  of  a  glass  vessel  which  is  half  filled 
with  nitric  acid  at  36°  or  40°  Be,  and  which  receives  a  hollow 
cylinder  of  pulverized  coke,  moulded  and  cemented  at  a  high 
temperature  by  sugar,  gum  or  tar.  At  the  upper  part  of  this 
cylinder,  where  it  does  not  dip  into  the  acid,  a  copper  collar  is 
fixed,  which  may  be  tightened  at  will  by  means  of  a  screw.  A 
copper  band  or  ribbon  is  fixed  to  the  collar,  and  may  be  con¬ 
nected  with  the  zinc  of  another  element.  A  porous  porcelain  cell 
is  placed  inside  the  coke  cylinder,  and  contains  a  dilute  solution 
of  sulphuric  acid  (1  part  acid  and  9  parts  water),  into  which  is  put 
a  bar  or  cylinder  of  zinc  strongly  amalgamated  or  covered  with  mer¬ 
cury.  When  a  battery  of  several  elements  is  to  be  formed  the  coke 
of  the  first  element  is  connected  with  the  zinc  of  the  second,  and 
so  on,  and  the  apparatus  is  completed  at  one  end  by  coke  com¬ 
municating  with  the  anode,  and  at  the  other  by  a  zinc  connected 
with  the  cathode  or  object  to  be  electroplated. 

A  modification  of  Bunsen’s  battery,  which  is  preferred  by  gold 
and  silver  electroplaters,  is  as  follows :  Each  element  is  composed 
of  an  exterior  vessel  or  pot,  most  generally  of  stoneware ;  a 
cylinder  of  zinc,  covered  with  mercury,  provided  with  a  binding 
screw  or  w'ith  a  copper  band,  whether  for  a  single  element  or  for 
the  end  of  a  combination  of  elements  in  a  battery,  or  to  connect 
the  zinc  with  the  carbon  of  another  element ;  a  porous  cell  of 
earthenware  pipe  or  porcelain  ;  a  cylinder  of  graphite,  made  from 
the  residue  found  in  old  gas  retorts.  The  graphite  is  bound  by  a 
copper  band  fixed  to  it  by  means  of  a  wire  of  the  same  metal,  all 
the  binding  being  afterwards  covered  with  a  thick  varnish  to  pro- 
21 


322 


THE  METAL  WORKER’S  HANDY-BOOK. 


tect  it  from  the  acid  fumes  of  the  battery  ;  notwithstanding  the 
varnish  the  acid  may  rise  by  capillary  attraction  and  corrode  the 
copper  band  between  the  carbon  and  the  wire  ;  therefore,  binding 
screws  of  various  shapes  and  sizes  should  be  used  to  connect  the 
carbon  or  zinc  by  means  of  ribbons  or  wires.  Use  conducting 
wires  of  pure  copper  covered  with  cotton,  silk,  india  rubber  or 
gutta-percha,  and  presenting  the  metal  at  their  extremities  in  order 
to  effect  the  connections.  Figs.  22,  23  and  24  show  the  three 
forms  of  Bunsen’s  elements  mostly  used. 


Other  batteries  used  are  Daniell’s,  Grove’s,  Grenet’s,  Srnee’s, 
Meidinger’s,  etc.,  but  for  a  description  of  these  and  of  dynamo- 
electric  machines  the  reader  is  referred  to  works  on  this  subject. 

Batteries  must  be  kept  in  a  place  where  the  temperature  does  not 
greatly  vary.  A  frost  arrests  their  action,  and  great  heat  increases 
it  too  much.  A  good  place  for  them  is  a  box,  and  they  are  put  at 
such  a  height  that  they  may  be  easily  manipulated.  This  box 
should  have  means  of  ventilation  in  such  away  that  the  air  coming 
in  at  the  lower  part  will  escape  at  the  top  through  a  flue  and  carry 
away  with  it  the  acid  fumes  constantly  disengaged.  It  is  best  to 
keep  the  batteries  in  a  room  different  from  that  where  the  baths 
and  metals  are  to  be  operated  upon,  as  these  are  easily  injured  by 
acid  vapors.  The  galvanic  current  may  be  conducted  into  the 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


323 


work-room  by  wires  passing  through  holes  in  the  wall  and  covered 
with  gutta-percha. 

Terms  Used  in  Electrolytic  Deposition  of  Metals. — i.  The  terms 
“cathode  ”  and  “  anode  ”  are  synonymous  with  the  positive  and 
negative  poles  of  an  electric  or  galvanic  battery. 

2.  To  measure  the  volume  of  electricity  passed  between  these 
points,  the  term  “  amperes  ”  is  used  as  the  unit,  like  feet  or  cubic 
feet,  for  measuring  in  the  usual  mechanical  sense. 

3.  For  expressing  the  force  with  which  the  volume  of  electricity 
is  propelled,  the  term  “  volt  ”  is  used  as  the  unit. 

4.  The  resistance  opposed  to  the  electricity  is  measured  by 
“  ohms.” 

5.  The  work  done  in  the  electrical  circuit  is  expressed  by 
“  watts,”  in  the  same  way  that  in  a  steam-engine  the  power  devel¬ 
oped  is  expressed  by  h.  p.  To  put  this  shortly : 

1  ampere  x  1  volt  =  1  watt. 

1  watt  x  746  =  E.  II.  P. 

These  are  the  electrical  terms  employed  by  common  consent  in 
all  European  languages  in  connection  with  this  science. 


Chemical  and  Electro-Chemical  Equivalents. 


Specific 

gravity. 

Chemical 

equivalent. 

Electro-chemical 

equivalent, 

milligrammes. 

Precipitate  by  1 
ampere  in  1  hour, 
in  grammes. 

Hydrogen. .  . . 

I 

I 

0.01036 

00375 

Aluminium  .  . 

2.6 

13-7 

0.14250 

°-5I37 

Antimony  .  .  . 

6.8 

122 

1.26880 

4-5750 

Arsenic . 

5-7 

7-5 

0.78000 

2.8125 

Cobalt . 

8-7 

29-5 

0.30680 

1.1062 

Copper . 

8.8 

31.8 

0.33070 

1.1925 

Iron . 

7-5 

28 

0.29120 

1.0500 

Gold . 

19.2 

98-3 

1.02230 

3.6862 

Lead . 

11  3 

1035 

1.07640 

3.8812 

Nickel . 

8.6 

29.5 

0.30680 

1.1062 

Platinum  .... 

21.2 

98.6 

1.02540 

3-^975 

Silver  . 

10.5 

108 

1.12320 

4.0500 

Tin . 

7-3 

327 

O.34OIO 

1.2262 

Zinc . 

7.2 

59 

0.61360 

2.2125 

324 


TI1E  METAL  WORKER’S  HANDY-BOOK. 


With  the  assistance  of  this  table  it  can  be  calculated  how  long  a 
measured  surface  has  to  remain  in  the  bath  in  order  to  acquire  a 
deposit  of  determined  weight  with  the  most  suitable  density  of 
current.  Suppose  the  time  is  to  be  determined  which  a  square 
decimeter  of  surface  has  to  remain  in  a  nickel  bath  in  order  to 
acquire  a  deposit  millimetre  thick  with  a  density  of  current  of 
0.5  ampere.  First  calculate  the  weight  of  the  precipitate  by 
multiplying  the  surface  in  square  millimetres  with  the  thickness 
and  specific  gravity.  One  square  decimetre  is  equal  to  10,000 
square  millimetres,  which,  multiplied  by  millimetre,  gives  as 
a  product  1,000,  which  multiplied  by  the  specific  gravity  of  nickel, 
8.6,  gives  8,600  milligrammes  —  8.6  grammes.  Hence  a  deposit 
y'ij  milligramme  thick  upon  a  surface  of  1  square  decimetre  repre¬ 
sents  the  weight  of  8.6  grammes.  Since  for  the  regular  deposit 
per  square  decimetre,  a  density  of  current  of  0.5  ampere  is  required, 
and  1  ampere  precipitates,  according  to  the  above  table,  1.1062 
gramme  in  1  hour,  *4  ampere  precipitates  0.5531  gramme  of 
nickel  in  1  hour,  and,  therefore,  about  16  hours  will  be  required  to 
precipitate  8.6  grammes. 

According  to  this  example  the  time,  for  instance,  can  also  be  cal¬ 
culated,  which  one,  two  or  more  dozens  of  knives  and  forks  or  spoons 
which  are  to  have  a  deposit  of  silver  of  a  determined  weight,  must 
remain  in  the  bath,  when  the  density  of  current  is  known.  Sup¬ 
pose  50  grammes  of  silver  are  to  be  deposited  upon  1  dozen  of 
spoons  and  the  most  suitable  density  of  current  is  0.2  ampere  per 
square  decimetre ;  if  the  surface  of  1  spoon  represents  1.10  square 
decimetre,  the  surface  of  1  dozen  spoons  of  equal  size  is  13.2 
square  decimetres.  Hence,  they  require  13.2  X  0.2  amperes  =  2.64 
amperes;  now,  since  1  ampere  precipitates  in  1  hour  4.05  grammes 
of  silver,  2.64  amperes  precipitate  in  the  same  time  10.7  grammes 
of  silver,  and  with  this  current  the  dozen  spoons  must  remain  about 
hours  in  the  bath  to  deposit  50  grammes  of  silver  upon  this 
surface. 

Preparation  of  Zinc  for  Batteries. — Melt  the  zinc  and  then  add 
tin  and  mercury;  next  pour  the  melted  mass  ip  moulds  and  heat 
until  a  portion  of  the  mercury  appears  upon  the  surface.  The 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


325 


pieces  while  still  hot  are  finally  subjected  to  the  action  of  a  weak 
acid  solution. 

Aluminium  Bath. — Aluminium  is  one  of  the  most  difficult  and 
uncertain  of  metals  to  deposit  electrolytically.  The  following 
receipt  is  given  by  Mr.  Herman  Reinbold,  who  states  that  it 
furnishes  excellent  results  :  50  parts  by  weight  of  alum  are  dis¬ 
solved  in  300  of  water,  and  to  this  are  added  10  parts  of  aluminium 
chloride.  The  solution  is  heated  to  200°  F.,  and  when  cold  39 
parts  of  cyanide  of  potassium  are  added.  A  feeble  current  should 
be  used. 

Antimony  Baths. — Galvanic  depositions  of  antimony  are  but 
seldom  made  use  of  in  the  industries,  though  they  are  very  suitable 
for  the  production  of  contrasts  in  decorating.  Gore  discovered 
the  explosive  power  of  depositions  of  solutions  of  antimony  chloride 
or  of  antimony  containing  hydrochloric  acid.  According  to 
Gore  a  bath  consisting  of  tartar  emetic  3  ozs.,  tartaric  acid  3  ozs., 
hydrochloric  acid  4*^  ozs.  and  water  1  quart,  yields  a  gray,  crys¬ 
talline  deposition  of  antimony.  This  bath  requires  a  current  of 
about  3  volts.  The  deposition  possesses  the  property  of  exploding 
when  scratched  with  a  hard  object. 

A  lustrous  non-explosive  deposition  of  antimony  is  obtained  by 
boiling  4.4  ozs.  of  carbonate  of  potash,  2.11  ozs.  of  pulverized 
antimony  sulphide  and  1  quart  of  water,  for  one  hour,  replacing 
the  water  lost  by  evaporation  and  filtering.  Use  the  bath  boiling 
hot,  employing  a  piece  of  antimony  as  anode.  The  separated 
antimony  has  the  color  of  polished  cast-iron,  and  takes  a  high 
polish. 

Arsenic  Baths. — Depositions  of  arsenic  are  frequently  used  for 
decorative  purposes,  for  instance,  to  color  gray  the  dead  back¬ 
ground  of  brassed  lamp-legs,  cans,  etc.,  while  the  prominent  por¬ 
tions  are  bright  brass.  A  good  arsenic  bath  is  as  follows  :  Prepare 
by  boiling  for  half  an  hour  and  filtering  a  solution  of  sodium 
arsenate  1^  ozs.,  potassium  cyanide  0.88  oz.,  and  water  1  quart. 
A  good  deposition  of  arsenic  is  obtained  with  a  strong  current  and 
having  the  bath  at  a  temperature  of  176°  F.  Use  a  platinum-sheet 
or  a  carbon  plate  from  natural  gas-coal  as  anode. 


326 


THE  METAL  WORKER’S  TI ANDY-BOOK. 


Another  Bath  is  composed  as  follows  :  Pulverized  arsenious  acid, 
x.  75  ozs.  ;  crystallized  sodium  pyrophosphate,  0.7  oz.  ;  98  per  cent, 
potassium  cyanide,  1.75  ozs.  ;  water,  1  quart.  Dissolve  the  sodium 
pyrophosphate  and  the  potassium  cyanide  in  the  cold  water,  then 
add,  with  constant  stirring,  the  arsenious  acid,  and  heat  until  the 
latter  is  dissolved.  The  bath  is  used  warm  and  requires  a  strong 
current  of  at  least  4  volts.  A  platinum-sheet  or  carbon-plate  is 
used  as  anode.  Large  baths,  which  are  preferably  used  cold, 
must  be  more  concentrated  and  require  a  stronger  current  than  the 
hot  baths. 

Brass  Baths. — A  good  brass  bath  is  composed  as  follows  :  Car¬ 
bonate  of  soda,  10342  ozs.;  bisulphate  of  soda,  7  ozs.  ;  neutral  acetate 
of  copper,  43^  ozs.  ;  chloride  of  zinc,  43^  ozs.  ;  98  per  cent,  po¬ 
tassium  cyanide,  14  ozs.;  arsenious  acid,  30^  grains;  water,.  10 
quarts.  Dissolve  the  carbonate  of  soda  in  5  quarts  of  the  water, 
and  then  add  gradually  the  bisulphate  of  carbon.  Now  stir  to¬ 
gether  the  acetate  of  copper  and  chloride  of  zinc  with  2  quarts  of 
the  water,  and  slowly,  and  with  constant  stirring,  pour  the  mixture 
into  the  solution  of  the  soda  salts.  Next  add  the  solution  of  the 
potassium  cyanide  in  3  quarts  of  the  water,  then  the  arsenious 
acid,  and  boil  the  whole  for  a  few  hours,  replacing  the  water  lost 
by  evaporation.  The  solution  when  cold  is  filtered. 

Brass-bath  from  Cupric  Sulphate  and  Zinc  Sulphate. — Dissolve 
ozs.  each  of  cupric  and  zinc  sulphate  in  5  quarts  of  warm 
water,  and  mix  the  solution  with  one  of  15^  ozs.  of  carbonate  of 
soda  in  5  quarts  of  water.  Allow  the  precipitate  of  carbonate  of 
copper  and  carbonate  of  zinc,  which  is  formed,  to  settle  for  12 
hours,  and  then  pour  off  the  supernatant  fluid.  Now  add  to  the 
precipitate  enough  water  to  bring  the  volume  up  to  8  quarts;  dis¬ 
solve  in  it  10 34  ozs.  of  carbonate  of  soda  and  7  ozs.  of  bisulphate 
of  soda,  and  finally  add  a  solution  of  ozs.  of  98  per  cent, 
potassium  cyanide  in  2  quarts  of  cold  water,  which  renders  the  fluid 
clear.  Before  boiling,  add  30^  grains  of  arsenious  acid. 

Brass-bath  for  Zinc. — Dissolve  93^  ozs.  of  crystallized  bisul¬ 
phate  of  soda  and  14  ozs.  of  70  per  cent,  potassium  cyanide  in  8 
quarts  of  water,  and  add  to  this  solution  one  of  43^  ozs.  each  of 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


327 


neutral  acetate  of  copper  and  crystallized  chloride  of  zinc,  5^  ozs. 
of  aqua  ammonia,  and  2  quarts  of  water. 

Brass-bath  for  Cast-iron,  Wrought-iron  and  Steel.  —  Dissolve 
35  %  ozs.  of  crystallized  carbonate  of  soda,  7  ozs.  of  crystallized 
bisulphate  of  soda,  13^  ozs.  of  98  per  cent,  potassium  cyanide  in 
8  quarts  of  water;  then  add,  with  constant  stirring,  a  solution  of 
melted  chloride  of  zinc  3^  ozs.,  neutral  acetate  of  copper  4 %  ozs., 
in  2  quarts  of  water;  boil  and  filter. 

Solution  for  Transferring  any  Copper-zinc  Alloy  serving  as  Anode. 
— Bisulphate  of  soda,  14^  ozs.  ;  crystallized  sal-ammoniac,  9)4 
ozs.  ;  98  per  cent,  potassium  cyanide,  2^  ozs.  ;  water,  10  quarts. 

The  color  of  the  brass  deposits  depends  on  the  proportional 
quantity  in  which  copper  and  zinc  are  present.  A  strong  current 
precipitates  more  zinc,  and  a  weaker  one  more  copper ;  the  deposit 
being  more  greenish  in  the  first  case,  and  more  reddish  in  the  lat¬ 
ter.  Hence  the  necessity  arises  of  regulating  the  current  so  that 
both  metals  are  precipitated  in  a  proportion  required  for  the  de¬ 
sired  color  of  the  deposit.  Formerly  the  color  was  obtained  by 
suspending  copper  and  zinc  anodes  in  the  bath,  and  allowing  the 
copper  anodes  to  dip  in  deeper  than  the  zinc  anodes  for  the  pro¬ 
duction  of  reddish  brass,  and  the  reverse  for  greenish  brass.  But 
at  the  present  time  the  different  colors  are  produced  in  one  bath 
with  brass  anodes,  by  diminishing  or  increasing  the  strength  of 
the  current  by  the  current-regulator,  which  renders  the  entire  pro¬ 
cess  more  simple  and  more  assured. 

Annealed  sheets  of  brass,  with  as  large  a  surface  as  possible,  are 
used  as  anodes.  To  increase  the  metallic  content  of  the  bath  it  is 
best  to  use  a  solution  of  cyanide  of  copper  and  cyanide  of  zinc  in 
potassium  cyanide,  adding  at  the  same  time  some  neutral  bisulphate 
of  soda,  while  a  thinly  fluid  paste  of  cyanide  of  copper  and  cyanide 
of  zinc  is  employed  for  the  removal  of  an  excess  of  potassium 
cyanide.  The  formation  of  slime  on  the  anodes  is  treated  in  the 
same  manner  as  given  for  copper  baths,  which  see. 

Brass  baths  showing  more  than  any  other  baths  the  peculiarity 
of  precipitating  in  an  irregular  manner,  when  freshly  prepared,  it 
is  absolutely  necessary  to  thoroughly  boil  them.  If  for  any  reason 


328 


TIIR  METAL  WORKER'S  II ANDY-BOOK. 


this  cannot  be  done,  they  must  for  some  time  be  thoroughly  worked 
through  with  the  current  before  a  regular  deposit  of  a  uniform 
color  can  be  obtained.  For  this  purpose  as  many  anodes  as  pos¬ 
sible  are  suspended  in  the  bath,  while  a  few  sheets  of  brass,  zinc 
or  iron  are  also  suspended  to  the  negative  pole.  A  sufficiently 
strong  current,  to  cause  a  vigorous  development  of  hydrogen  on 
the  cathodes,  is  then  conducted  through  the  bath.  A  test  is  from 
time  to  time  made,  to  see  whether  the  bath  works  in  a  regular 
manner,  and  when  this  is  the  case  the  sheets  are  removed  from  the 
negative  pole  and  the  operation  is  commenced. 

According  to  their  composition  brass  baths  require  a  tension  of 
current  of  3  to  4  volts,  and  an  intensity  of  0.5  to  0.6  ampere  per 
15*4  scluare  inches. 

Cobalt  Baths. — Nickel  being  cheaper  than  cobalt  and  its  color 
somewhat  whiter,  electro-plating  with  this  metal  is  but  little  prac¬ 
tised.  On  account  of  its  greater  solubility  in  dilute  sulphuric  acid 
it  is,  however,  under  all  circumstances  to  be  preferred  for  coating 
valuable  copper-plates  for  printing.  Gaiffe  recommends  for  this 
purpose  a  solution  of  1  part  of  chloride  of  cobalt  in  10  of  water. 
The  solution  is  to  be  neutralized  with  aqua  ammonia,  and  the 
plates  are  to  be  electro-plated  with  the  use  of  a  moderate  current. 

Cobalt  precipitated  from  a  chloride  solution  does  not  yield,  how¬ 
ever,  a  hard  coating,  and  hence  the  following  bath  is  recommended 
for  the  purpose:  Double  sulphate  of  cobalt  and  ammonium,  21 
ozs.  ;  cobaltous  carbonate,  0.8  oz.  ;  crystallized  boric  acid,  10^ 
ozs.  ;  water,  10  quarts.  This  bath  requires  a  current  of  2.5  to  2.75 
volts. 

Warren  has  recently  described  a  solution  of  cobalt  which  can  be 
decomposed  in  a  simple  cell  apparatus,  and  for  this  reason  would 
seem  to  be  suitable  for  electro-plating  small  articles  en  masse. 
For  the  preparation  of  the  bath  dissolve  3*4  ozs.  of  chloride  of 
cobalt  in  as  little  water  as  possible,  and  compound  the  solution 
with  a  concentrated  solution  of  Rochelle  salt  until  the  voluminous 
precipitate  at  first  formed  is  almost  entirely  redissolved,  and  filter. 
Bring  the  bath  into  a  vessel  and  place  the  latter  in  a  clay  cell,  filled 
with  concentrated  solution  of  sal-ammoniac  or  common  salt,  and 


ELECTROPLATING,  BRASSING,  COPPERING,  ETC. 


329 


containing  a  zinc  cylinder.  Connect  the  articles  to  be  electro¬ 
plated  by  a  copper  wire  to  the  zinc,  and  allow  the  articles  to  dip 
in  the  cobalt  solution. 

Electro-plating  with  Cobalt  by  contact. — While  nickelling  by 
touching  with  zinc  yields  only  incomplete  results,  the  electro¬ 
plating  with  cobalt  of  copper  and  brass  articles  succeeds  very  well 
with  the  use  of  the  following  bath  :  Crystallized  cobalt  sulphate, 
0.35  oz. ;  crystallized  sal-ammoniac,  0.7  oz. ;  water,  1  quart.  Heat 
the  bath  to  between  104°  and  1220  F.,  and  immerse  the  previously 
cleansed  and  pickled  articles  in  the  bath,  bringing  them  in  contact 
with  a  bright  zinc  surface ;  for  small  articles  a  zinc  sieve  may  be 
used.  In  3  or  4  minutes  the  coating  is  thick  enough  to  bear  vigor¬ 
ous  polishing. 

Copper  Baths. — The  composition  of  these  baths  depends  on  the 
purpose  for  which  they  are  to  serve,  and  in  the  following  the  most 
approved  baths  are  mentioned,  with  the  exception  of  the  acid  cop¬ 
per  bath,  which  is  used  for  plastic  deposits  of  copper. 

In  most  cases  the  more  electro-positive  metals — zinc,  iron,  tin, 
etc. — are  to  be  coppered,  either  as  a  preparation  for  the  succeeding 
process  of  nickelling,  silvering,  or  gilding,  or  to  protect  them 
against  oxidation  by  a  thick  deposit  of  copper.  The  above- 
mentioned  electro-positive  metals,  however,  decompose  the  acid 
copper  solutions,  and  separate  from  them  pulverulent  copper,  while 
an  equivalent  portion  of  zinc,  iron,  tin,  etc.,  is  dissolved.  For 
this  reason  such  solutions  of  copper  cannot  be  used  for  coating 
these  metals,  alkaline  copper  baths  being  exclusively  employed  for 
the  purpose,  which  may  be  arranged  in  two  groups — into  those 
containing  potassium  cyanide  and  into  those  without  it. 

Hassauer  prepares  a  copper  bath  by  dissolving  2P/2  ozs.  of  copper 
cyanide  in  a  solution  of  17.5  ozs.  of  70  per  cent,  potassium  cyanide, 
in  3  quarts  of  water,  boiling,  filtering,  and  diluting  with  7  quarts 
of  water  to  a  10-quart  bath.  This  bath  works  very  well  when 
heated  to  between  1130  and  1220  F.,  but  when  used  cold  requires 
a  very  strong  current. 

Copper  Baths  for  Iron  and  Steel  Articles. — I.  To  be  Used  at  an 
Ordinary  Temperature. — Water,  10  quarts  ;  crystallized  bisulphate 


330 


THE  METAL  WORKER’S  ITANDY-BOOK. 


of  soda,  7  ozs.  ;  crystallized  carbonate  of  soda,  14  ozs.  ;  neutral 
acetate  of  copper,  7  ozs.  ;  75  per  cent,  potassium  cyanide,  7  ozs.  ; 
spirit  of  sal-ammoniac,  4.4  ozs. 

II.  To  be  Used  at  front  140°  to  158°  F. — Water,  10  quarts; 
crystallized  bisulphate  of  soda,  2^  ozs.  ;  crystallized  carbonate  of 
soda,  7  ozs.  ;  neutral  acetate  of  copper,  7  ozs.  ;  75  per  cent, 
cyanide  of  potassium,  9^  ozs.  ;  spirit  of  sal-ammoniac,  4  ozs. 
The  baths  are  best  prepared  as  follows :  Dissolve  the  bisulphate 
and  carbonate  of  soda  in  one-half  the  water,  the  potassium  cyanide 
in  the  other  half,  and  mix  the  copper  salt  with  the  spirit  of  sal- 
ammoniac  ;  then  pour  the  blue  ammoniacal  copper  solution  into 
the  solution  of  the  soda  salts,  and  finally  add  the  potassium  cyanide 
solution  ;  the  bath  will  be  clear  and  colorless.  Boiling,  though 
not  absolutely  necessary,  is  of  advantage,  after  which  the  solution 
is  to  be  filtered. 

The  following  formula  is  highly  recommended :  Water,  xo 
quarts ;  crystallized  carbonate  of  soda,  8)4  ozs.  ;  crystallized  bi¬ 
sulphate  of  soda,  7  ozs.  ;  neutral  acetate  of  copper,  7  ozs. ;  98  or 
99  per  cent,  potassium  cyanide,  8)4  ozs.  The  bath  is  prepared  as 
follows  :  Dissolve  in  7  quarts  of  warm  water  the  carbonate  of  soda, 
gradually  add  the  bisulphate  of  soda  to  prevent  violent  effer¬ 
vescence,  and  then  add,  with  vigorous  stirring,  the  acetate  of  cop¬ 
per  in  small  portions.  Dissolve  the  cyanide  of  potassium  in  3 
quarts  of  cold  water,  and  mix  both  solutions  when  the  first  is  cold. 
By  thorough  stirring  with  a  clean  wooden  stick  a  clear  solution  is 
obtained,  which  is  best  boiled  for  half  an  hour,  and  then  filtered. 

For  small  zinc  articles  which  are  to  be  coppered  in  a  sieve,  the 
bath  is  warmed  and  a  little  more  potassium  cyanide  added. 

Instead  of  acetate  of  copper  cupric  sulphate  (blue  vitriol)  may  be 
used  for  preparing  the  baths,  the  following  formula  being  especially 
suitable  for  the  purpose:  Dissolve  10  )4  ozs.  of  cupric  sulphate  and 
14  ozs.  of  carbonate  of  soda,  each  by  itself,  in  hot  water,  and  mix 
both  solutions;  allow  the  precipitate  of  carbonate  of  copper  which 
is  formed  to  settle  and  pour  off  the  clear  supernatant  fluid.  To  the 
precipitate  add  7  quarts  of  water,  then  gradually  8)4  ozs.  of  car¬ 
bonate  of  soda  and  7  ozs.  of  bisulphate  of  soda,  and  mix  this  solu- 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


331 


tion  with  one  of  ozs.  of  98  per  cent,  potassium  cyanide  in  3 
quarts  of  water.  After  mixing,  the  discoloration  of  the  fluid  takes 
place  rapidly,  when  it  is  boiled  and  filtered. 

Annealed  sheets  of  pure  copper  with  as  large  a  surface  as  possible 
serve  as  anodes.  They  become  gradually  covered  with  a  green 
slime,  which  must  from  time  to  time  be  removed  by  scouring  with 
sand.  When  a  very  strong  and  rapid  formation  of  slime  takes 
place  and  the  bath  becomes  bluish,  potassium  cyanide  is  wanting 
and  must  be  added.  Too  large  an  excess  of  potassium  cyanide 
causes  strong  development  of  hydrogen  and  no  deposition,  or  only 
a  very  slight  one,  takes  place,  which  besides  has  the  tendency  to 
peel  off.  Such  excess  can  be  readily  removed  by  the  addition  of 
cyanide  of  copper,  stirred  with  water  to  a  thinly  fluid  paste.  As 
the  anodes  are  not  able  to  keep  the  content  of  copper  in  the  bath 
constant,  there  being  not  as  much  copper  dissolved  from  them  as  is 
precipitated,  the  content  of  metal  in  the  bath  must  be  increased, 
when  it  commences  to  work  slowly,  by  the  addition  of  solution  of 
cyanide  of  copper  in  potassium  cyanide;  it  is  also  advisable  to  add 
at  the  same  time  some  neutral  bisulphate  of  soda. 

The  deposit  of  copper  is  thoroughly  brushed  with  a  soft  brass 
scratch-brush,  the  article  is  then  returned  to  the  bath,  and  again 
scratch-brushed,  this  being  repeated  until  the  deposit  is  of  sufficient 
thickness.  The  coppered  articles  are  then  immersed  in  hot  water, 
dried  in  saw-dust,  and  finally  polished  dry  with  Vienna  lime  upon 
fine  flannel  disks.  The  polished  articles  are  lastly  coated  with  a 
colorless  lacquer  to  prevent  oxidation  in  the  air. 

Copper  Bath  without  Potassium  Cyanide. — Dissolve  52^  ozs.  of 
potassium  sodium  tartrate  (Rochelle  salts),  jo1/^  ozs.  of  cupric  sul¬ 
phate,  28  ozs.  of  caustic  soda  in  10  quarts  of  water. 

The  Ehnore  Process  of  Electro-depositing  Copper  for  Tubes  and 
Wire  Bars. — A  revolving,  cylindrical  mandril  of  iron  is  placed  in 
an  electrolytic  vessel  containing  solution  of  cupric  sulphate. 
Around  the  mandril  are  arranged  bars  of  copper,  which  communi¬ 
cate  with  the  positive  pole  of  a  dynamo  whilst  the  mandril  com¬ 
municates  with  the  negative  pole.  The  copper  deposits  upon  the 
bottom,  and  when  the  deposit  has  acquired  sufficient  thickness  the 


332 


TITE  METAL  WORKER’S  II ANDY- BOOK. 


tube  is  withdrawn,  which  thus  has  been  finished  without  soldering. 
To  impart  to  the  deposited  copper  tenacity  and  ductility  its  surface 
is  rubbed  with  a  polishing-stone.  The  agate  used  as  a  polishing- 
stone  presses  lightly  upon  the  surface  of  the  copper,  being  in  con¬ 
tinual  operation  from  one  end  of  the  revolving  mandril  to  the  other. 
The  velocity  of  both  is  so  regulated  that  the  entire  surface  of  the 
deposit  is  rubbed  by  the  polishing-stone,  and  that  the  thin  layers 
successively  deposited  are  suitably  polished  and  acquire  the  neces¬ 
sary  mechanical  properties.  The  impurities  of  the  copper  thus 
electrolyzed  and  purified  fall  to  the  bottom  of  the  electrolytical 
vessel,  from  whence  they  are  removed,  washed,  dried,  and  melted, 
to  be  finally  treated  for  the  recovery  of  gold  and  silver. 

By  the  nature  of  the  above-described  process  the  copper  is  neces¬ 
sarily  and  unavoidably  pure ;  and  is,  therefore,  especially  adapted 
for  cable  and  other  electrical  purposes.  Special  machinery  has 
been  arranged  so  that  an  electro-burnished  tube  produced  by  the 
above-mentioned  method  may  be  cut  spirally  into  a  square  wire, 
which  can  then  be  drawn  down  in  the  usual  manner  to  any  required 
diameter.  The  wire  being  drawn  directly  from  the  electro-burnished 
tube  obviates  entirely  the  necessity  for  melting,  and  thus  constitutes 
altogether  a  new  departure  in  the  manufacture  of  pure  copper  wire. 
Some  of  the  tests  to  which  it  has  been  subjected  are  very  interest¬ 
ing.  Two  large  coils  of  the  new  wire  were  taken,  the  wire  of  the 
first  having  a  diameter  of  0.113  inch  (about  12  Birmingham  wire 
gauge),  and  the  second  a  diameter  of  0.05  inch  (about  18  B.  W. 
G.),  both  being  extremely  hard  drawn.  In  order,  however,  to  be 
perfectly  satisfied  that  the  practical  limit  of  hardness  had  been 
reached,  the  larger  wire  was  drawn  through  13  holes  in  a  draw- 
plate  (the  last  hole  being  of  agate)  without  annealing,  until  the 
diameter  of  the  wire  was  reduced  to  0.057  inch.  Its  hardness  may 
be  judged  of  by  the  fact  that  the  breaking-strain  was  29  tons  per 
square  inch,  with  an  elongation  of  only  ^  per  cent.  The  No.  18 
B.  W.  G.  wire  had  a  breaking-strain  of  nearly  29  tons  per  square 
inch,  with  an  elongation  of  only  3/&  per  cent.  When  these  wires 
were  annealed  they  showed  an  elongation  of  25  to  33  per  cent, 
before  breaking. 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


333 


Dr.  Matthiessen  found  that  the  purer  the  metal  was  obtained  the 
greater  was  the  variation  of  its  electrical  resistance  with  correspond¬ 
ing  variations  of  temperature,  and  gave  the  general  law  as  Rt  =  Ro 
(i  +  at  -f  b  t2)  where  Ro  is  the  resistance  of  the  metal  or  alloy  at 
the  temperature  of  0°  C.,  and  Rt  the  resistance  of  any  temperature 
t  degrees  C.  above  0°.  He  found  that  for  most  pure  metals  the 
value  of  a  was  0.003824  t,  and  b  0.00000126  t2  with  the  sign  -f- 
between  them.  The  experiments  carried  out  on  the  new  wire  are 
confirmatory  of  its  great  purity,  as  these  coefficients  are  found  to  be 
distinctly  higher,  the  expression  for  it  being  Rt  =  Ro  (1  -f- 
0.0041158  t  -f-  0.000003077  t2). 

The  results  of  the  conductivity  tests  are  given  in  the  first  table. 
The  conducting  power  of  the  hardest  wire  is  so  high  that,  with  a 
breaking  strain  of  29  tons  per  square  inch,  it  has  a  conductivity 
about  2^/2  per  cent,  higher  than  that  of  soft  annealed  wire  of  the 
best  quality  hitherto  obtained  commercially  (say  98  per  cent.). 
When  the  new  wire  is  annealed  it  has  a  conducting  power  4^  per 
cent,  above  the  best  commercial  copper. 


Gauge  (ap- 

Conductivity  of  annealed 

Conductivity  of  annealed 

Diameter. 

proximate) 

wire  in  terms  of  standard 

wire  in  terms  of  standard 

B.  W.  G. 

for  annealed  copper. 

for  hard  copper. 

in. 

0.113 

12 

102  33 

10439 

0.057 

17 

102.35 

IO4.4I 

0.049 

18 

102  45 

104.51 

Mean . 

102.38 

The  following  mechanical  tests 

have  been  made  on 

the  wire, 

each  result 

being  the 

mean  of  three  experiments  : 

Breaking  strain. 

Number  of 

Weight  per 

/ - * - 

Elonga- 

twists  in 

Diameter. 

statute  mile. 

Observed.  Per  sq.  in. 

tion. 

3  inches. 

In. 

Lb. 

Lb. 

Tons. 

Per  cent. 

0.113 

205.0 

612 

27.4 

2 

31 

0.082 

IIO.O 

375 

31.2 

42 

0.057 

52.8 

166 

28.7 

Y 

not  taken. 

0.05 

40.8 

127 

28.4 

H 

47 

334 


THE  METAL  WORKER'S  HANDY-BOOK. 


The  wire  was  also  tested  as  follows :  It  was  wrapped  six  times 
around  its  own  circumference,  as  in  making  a  “bell-hanger’s 
joint.”  It  was  then  unwrapped,  wrapped  again,  and  so  on  until 
the  wire  broke.  The  results  were : 


Wrappi 

ng  and  Unwrapping. 

In. 

No. 

on 

off 

on 

off 

on 

off 

on 

off 

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r 

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6 

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6 

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0.113I 

2 

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6 

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6 

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6 

6 

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6 

6 

6 

6 

6 

6 

6 

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6 

6 

6 

6 

6  ' 

3 

0.05 

1 

2 

6 

6 

6 

6 

6 

6 

6 

4 

l 

3 

6 

6 

6 

6 

6 

6 

6 

6 

It  will  thus  be  seen  that  the  hard  wire  is  admirably  adapted  for 
over-head  telegraph  wires,  possessing  the  two  requisites  of  great 
strength  and  high  conductivity.  The  efficiency  of  dynamo  ma¬ 
chines  and  electrical  instruments  can  be  increased,  because  a  greater 
number  of  “ampere-turns”  can  be  got  within  a  given  space. 
The  copper  tape  or  riband  used  so  extensively  for  lightning  con¬ 
ductors  can  be  cut  direct  from  the  tube,  of  any  length  and  sec¬ 
tional  area,  by  the  special  machinery  before  mentioned.  It  would 
take  up  too  much  space  to  dilate  upon  the  enormous  demands  for 
pure  copper  that  must  arise,  due  to  the  development  of  the  indus¬ 
trial  application  of  electricity. 

To  get  a  Copper  Deposit  on  Wax.- — Coat  the  wax  with  black- 
lead  ;  brush  the  wax  over  with  alcohol,  and  follow  with  black-lead 
plumbago,  rubbing  with  a  soft  brush.  The  deposit  is  made  from 
a  saturated  solution  of  sulphate  of  copper  (blue  vitriol)  in  water; 
the  solution  should  stand  for  24  hours,  and  be  stirred  occasionally 
before  using.  A  copper  wire  is  melted  into  the  wax  and  the  black- 
lead  well  worked  with  the  brush  over  it,  so  as  to  make  an  electric 
connection  between  the  wire  and  the  wax.  The  copper  plate 
placed  in  the  solution  from  which  the  copper  is  dissolved  to  keep 
up  the  strength  of  the  solution,  is  attached  to  the  carbon  or  cop¬ 
per  pole  of  the  battery  and  the  wax  to  the  zinc  pole. 

Brush-coppering  for  Iron  and  Steel. — This  process  can  be  rec- 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


335 


ommended  for  its  simplicity  and  general  applicability.  The 
utensils  required  are  two  vessels  of  sufficient  size,  each  provided 
with  a  brush  preferably  so  wide  that  the  entire  surface  of  the  article 
to  be  treated  can  be  coated  with  one  application.  One  of  the 
vessels  contains  a  strongly  saturated  solution  of  caustic  soda,  and 
the  other  a  strongly  saturated  solution  of  cupric  sulphate  (blue 
vitriol)  of  the  best  quality. 

For  coppering,  the  well-cleansed  article  is  first  uniformly  coated 
with  a  brush  full  of  the  caustic  soda  solution,  and  then  also  with  a 
brushful  of  the  copper  solution.  A  quite  thick  film  of  copper  is 
immediately  firmly  deposited  upon  the  article.  Care  must  be  had 
not  to  take  the  brush  too  full,  and  not  to  touch  the  places  once 
gone  over  the  second  time,  as  otherwise  the  layer  of  copper  does 
not  adhere  firmly.  The  coppering  thus  produced  is  so  strong  and 
durable  that,  without  fear  of  injury,  the  articles  may  afterwards  be 
scratch-brushed,  gilded  and  silvered,  and  also  colored  brown  or 
steel-blue. 

For  coloring,  the  following  directions  are  given  :  For  brown, 
dissolve  6.77  drachms  of  calcium  monosulphide  and  1  oz.  6 
drachms  of  powdered  sal-ammoniac  in  10  quarts  of  water.  Small 
articles  are  dipped  into  this  solution  and  large  ones  brushed  over 
with  it.  After  dipping,  the  articles  are  to  be  thoroughly  scratch- 
brushed,  as  they  show  various  colors  when  they  come  from  the 
bath,  and  acquire  a  uniform  tone  only  by  scratch-brushing. 

For  Dai'k-steel  Blue. — Dissolve  from  12  drachms  to  1  oz.  of 
potassium  sulphide  and  the  same  quantity  of  common  salt  in  10 
quarts  of  water.  The  bath  is  used  in  the  same  manner  as  for 
brown. 

This  process  can  be  especially  recommended  for  articles  which 
are  to  be  decorated  in  several  colors.  By  only  partially  gilding  or 
entirely  silvering  such  articles,  very  beautiful  effects  can  be  pro¬ 
duced  by  the  use  of  the  above-described  method,  which,  with  some 
experience,  is  less  difficult  to  execute  than  coppering  by  the  gal¬ 
vanic  current  or  by  immersion. 

How  to  Copper  Iron. — Iron  can  be  coppered  by  dipping  it  into 
melted  copper,  the  surface  of  which  is  protected  by  a  melted  layer 


336 


THE  METAL  WORKER’S  HANDY-BOOK. 


of  cryolite  and  phosphoric  acid ;  the  articles  to  be  thus  treated 
being  heated  to  the  same  temperature  as  the  melted  copper.  An¬ 
other  process  consists  in  dipping  the  articles  into  a  melted  mixture 
of  i  part  of  chloride  or  fluoride  of  copper,  5  or  6  parts  of  cryolite, 
and  a  little  chloride  of  barium.  If  the  article,  when  immersed,  is 
connected  with  the  negative  pole  of  a  battery,  the  process  is  has¬ 
tened.  A  third  method  consists  in  dipping  the  articles  in  a  solution 
of  oxalate  of  copper  and  bi-carbonate  of  soda,  dissolved  in  10  or 
15  parts  of  water,  acidified  with  organic  acid. 

To  Copper  Iron  and  Steel. — First  free  the  objects  of  cast-iron, 
steel  or  wrought-iron  from  rust,  and  then  brush  them  thoroughly 
with  a  brush  of  hard  bristles  dipped  in  pulverized  tartar  saturated 
with  cupric  sulphate  (blue  vitriol).  The  articles  thus  treated  will 
be  coated  with  a  thin,  uniform  and  firmly  adhering  layer  of 
copper. 

To  Copper  Cast-iron. — To  provide  cast-iron  articles  with  a 
beautiful  and  durable  coating  of  copper  proceed  as  follows:  Scour 
the  article  with  a  pickle  consisting  of  50  parts  of  hydrochloric  acid 
of  15°  Be.  and  1  part  of  nitrate  of  copper.  Then  rub  them  with 
a  woollen  rag  or  a  soft  brush  dipped  in  a  solution  of  10  parts  of 
nitrate  of  copper  and  a  like  quantity  of  cupric  chloride  in  80  parts 
of  nitric  acid  of  150  Be.  After  a  few  seconds  rinse  the  articles  in 
clean  water  and  polish  them  with  a  dry  woollen  rag.  This  rubbing 
and  subsequent  polishing  is  repeated  until  the  layer  of  copper  is 
of  the  desired  thickness.  In  this  manner  ground  or  rough 
objects  can  be  entirely  or  partially  coppered,  the  process  being 
recommendable  on  account  of  its  simplicity,  cheapness  and  the 
durability  of  the  coppering.  To  give  articles  thus  coppered  the 
appearance  of  antique  bronze,  touch  them  up  with  a  solution  of  4 
parts  of  sal-ammoniac,  1  part  of  oxalic  acid  and  1  part  of  acetic 
acid  in  30  parts  of  water,  the  operation  being  repeated  until  the 
object  has  acquired  the  desired  color. 

To  Coat  Iron  Articles  with  Copper,  Brass  or  Bronze. — W.  Tyth- 
erbigh,  of  Birmingham,  England,  proceeds  as  follows  :  The  sheets 
are  first  pickled  and  then  uniformly  covered  with  a  layer  of  brass- 
filings  upon  which  borax  is  scattered.  The  sheets  thus  prepared  are 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC.  337 

«» 

next  brought  into  a  furnace  heated  to  the  proper  degree.  The  union 
of  the  two  metals  takes  place  by  the  fusion  of  the  brass,  the  time 
required  for  the  process  being  only  about  ten  seconds.  The  union 
is  very  complete,  so  that  the  sheet  can  at  will  be  rolled,  stamped, 
annealed,  etc.,  without  fear  of  a  separation  of  the  two  metals,  and 
the  brass  can  only  be  removed  from  the  iron  by  filing.  This  pro¬ 
cess  is  especially  suitable  for  ship-sheathing.  For  coating  small 
cast  or  wrought-iron  articles  with  copper,  brass,  bronze  or  a  similar 
alloy  another  method  is  employed.  The  metal  or  alloy  with  which 
the  iron  is  to  be  coated  is  melted  with  an  addition  of  borax  in 
suitable  iron  or  clay  vessels,  the  thoroughly  cleansed  articles  are 
then  dipped  into  the  bath  and  are  moved  to  and  fro  so  that  they 
acquire  the  heat  of  the  metal  and  become  coated  with  it.  They 
are  then  taken  out  and  allowed  to  cool  upon  a  grate,  they  being 
moved  about  until  the  coating  congeals.  Larger  articles  are  heated 
before  placing  them  in  the  melted  metal. 

To  Coat  Tin ,  Cast-iron  or  Zinc  with  Copper. — The  bath  can  be 
used  cold  as  well  as  warm,  and  consists  of  sodium  sulphide,  10.58 
ozs.  ;  75  per  cent,  cyanide  of  potash,  17.63  ozs.  ;  acetate  of 
copper,  12.34  ozs.  ;  ammonia,  7.05  ozs.  ;  and  water,  55  lbs.  A 
bath  for  smaller  articles  of  zinc,  which  are  generally  coppered  at  a 
boiling  heat  in  a  strainer,  consists  of  sodium  sulphide,  3.52  ozs.  ; 
cyanide  of  potash,  24.69  ozs.  ;  acetate  of  copper,  15.87  ozs.  ; 
ammonia,  5.29  ozs.  ;  and  water,  44  to  55  lbs.  The  acetate  of 
copper  is  dissolved  by  itself  in  5  quarts  of  water  and,  after  mixing 
it  with  the  ammonia,  added  to  the  other  solution.  When  cyanide 
of  potash  of  unknown  content  is  used,  its  solution  is  added  last 
until  the  fluid  is  entirely  discolored. 

To  Copper  Zinc  Plates. — To  coat  a  zinc  plate  with  a  hard 
though  very  thin  layer  of  copper,  dip  it  into  a  bath  composed  of 
100  parts  of  water  saturated  with  cupric  chloride  (40  cupric 
chloride  and  60  water),  150  parts  of  ammonia  and  3000  of  water. 
For  very  solid  coppering  use  the  above  described  bath,  which  has 
a  fine  blue  color,  and  add  a  saturated  solution  of  prussiate  of  potash 
in  water  until  the  blue  color  of  the  first  mixture  has  quite  dis¬ 
appeared.  This  process  of  coppering  is  somewhat  slower  than  by 
22 


338 


THE  METAL  WORKER’S  HANDY-BOOK. 


the  galvanic  way,  but  yields  nearly  as  solid  results.  For  plates 
engraved  with  the  graver,  or  stamped,  it  is  best  to  use  a  mixture 
of  prussiate  of  copper  with  neutral  potassium  sulphate,  to  which  is 
added  another  mixture  of  cupric  sulphate  (blue  vitriol)  dissolved 
to  saturation  in  water,  and  of  water  saturated  with  prussiate  of 
potash.  After  the  complete  solution  of  the  precipitate  and  dis¬ 
coloration  of  the  fluid,  the  bath  is  ready  for  use.  By  now  adding 
to  the  above-mentioned  reagents,  sulphate  or  chloride  of  zinc,  a 
very  good  brass  bath  is  obtained  which  is  allowed  to  act  upon  the 
zinc  plate  by  means  of  a  single  electric  element.  Instead  of  using 
completely  saturated  baths  one-quarter  to  one-third  of  their  volume 
of  ordinary  water  may  be  added  to  them.  For  hard  coppering  the 
second  bath  is  the  most  suitable,  it  yielding  very  satisfactory  results, 
and  as  it  is  known  to  contain  prussiate  of  potash  there  is  no  danger, 
provided  care  be  exercised. 

Gold-baths. — There  are  a  large  number  of  receipts  for  gold- 
baths,  and  only  the  most  approved  will  be  mentioned  in  the  follow¬ 
ing.  Baths  for  electro-gilding  are  used  either  cold  or  warm. 
Warm  gold-baths  need  not  to  be  so  rich  in  gold  as  cold  baths,  re¬ 
quire  less  strength  of  current,  and,  generally  speaking,  yield  denser 
depositions  of  warmer  tones.  By  using  pure  gold  solution,  Which 
contains  no  other  metal,  the  separated  gold  has  the  pure  yellow 
color  characteristic  of  fine  gold ;  for  a  more  reddish  or  more 
greenish  color,  i.  e.,  the  color  of  gold  alloyed  with  copper  or  silver, 
a  bath  containing  copper  or  silver  besides  gold  has  to  be  used. 
Some  electro-platers  prefer  baths  prepared  with  potassium  cyanide, 
others  those  prepared  with  potassium  ferro- cyanide.  The  first  are 
considered  the  most  profitable. 

It  does  not  pay  to  dissolve  the  gold  for  the  baths,  since  chloride 
of  gold  of  great  purity  can  be  procured  from  chemical  factories. 
Brown  neutral  chloride  of  gold  should  be  asked  for,  the  crystal¬ 
lized,  orange-color  salt  containing  too  much  acid. 

The  most  simple  gold-bath  consists  of  neutral  chloride  of  gold, 
0.35  oz.  ;  99  per  cent,  potassium  cyanide,  0.7  oz.  ;  and  water,  1 
quart.  Dissolve  the  potassium  cyanide  in  one-half  of  the  water 
and  the  chloride  of  gold  in  the  other  half;  mix  both  solutions  and 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


339 


boil  for  half  an  hour,  replacing  the  water  lost  by  evaporation. 
The  color  of  the  deposition  of  gold  yielded  by  this  bath  is,  how¬ 
ever,  not  so  warm  as  when  the  following  bath  is  used  for  cold 
electro-gilding : 

Dissolve  0.24  oz.  of  neutral  chloride  of  gold  in  1  pint  of  water 
and  add  spirit  of  sal-ammoniac  as  long  as  a  yellow  precipitate  of 
fulminating  gold  is  formed.  Then  filter  off  and  wash  the  pre¬ 
cipitate  in  the  filter  with  distilled  water,  rinse  the  residue  from  the 
filter  into  a  porcelain  dish,  and  add  water  until  the  volume  amounts 
to  1^2  pints.  Then  dissolve  in  y,  pint  of  water  y2  oz.  of  99  per 
cent,  potassium  cyanide,  add  this  solution  to  the  first  and  boil,  with 
constant  replacement  of  the  water  lost  by  evaporation,  until  the 
fluid  shows  no  odor  of  ammonia. 

One  quart  of  this  bath  prepared  from  fulminating  gold  mixed 
with  3  quarts  of  distilled  water  gives  an  excellent  bath  for  warm 
electro-gilding,  for  which  purpose  it  is  to  be  heated  to  between  158° 
and  167°  F. 

Too  large  an  excess  of  potassium  cyanide  in  the  gold  baths  must 
be  avoided,  it  causing  a  pale  color  in  the  gilding. 

Another  bath  suitable  for  electro-gilding  is  as  follows :  Chemi¬ 
cally  pure  sodium  phosphate,  2. 1 1  ozs.  ;  neutral  sodium  sulphide, 
0.35  oz.  ;  99  per  cent,  potassium  cyanide,  0.7  oz.  ;  neutral  chloride 
of  gold,  0.7  oz.  ;  and  distilled  water,  1  quart.  The  salts  are  dis¬ 
solved  in  the  order  mentioned,  in  the  cold  water.  The  bath  is  used 
at  a  temperature  of  from  158°  to  167°  F.  If  it  is  to  be  used  for  the 
direct  gilding  of  iron  and  steel,  only  0.18  to  0.35  oz.  of  potassium 
cyanide  is  taken  instead  of  0.7  oz. 

A  formula  for  a  cold  bath  prepared  with  potassium  ferrocyanide 
instead  of  potassium  cyanide  is  as  follows :  Yellow  prussiate  of 
potash,  0.56  oz.  ;  sodium  carbonate,  0.56  oz.  ;  fine  gold  (in  the 
form  of  chloride  of  gold  or  fulminating  gold),  0.7  oz.  ;  water,  1 
quart.  Heat  the  solution  of  the  yellow  prussiate  of  potash  and  of 
the  sodium  carbonate  in  the  1  quart  of  water  to  boiling,  then  add 
the  gold  salt,  and  boil  for  %  hour,  or  with  the  use  of  freshly  pre¬ 
cipitated  fulminating  gold,  until  the  disappearance  of  the  ammonia 
odor.  When  cold  the  solution  is  mixed  with  a  quantity  of  distilled 


340 


THE  METAL  WORKER’S  HANDY-BOOK. 


water  corresponding  to  the  quantity  of  water  lost  by  evaporation, 
and  filtered.  This  bath  gives  a  good  gilding  upon  all  metals, 
including  steel  and  iron.  Suitable  strength  of  current,  3.25  to  3.5 
vol  ts. 

Many  electro-platers  prepare  the  gold  baths  with  the  assistance 
of  the  electric  current.  For  this  purpose  prepare  a  solution  of  3.52 
ozs.  of  potassium  cyanide  (98  to  99  per  cent.)  per  quart  of  water, 
and  after  heating  to  from  1220  to  140°  F.,  conduct  the  current  of 
two  Bunsen  elements  through  two  sheets  of  gold,  not  too  small, 
which  are  suspended  as  electrodes  in  the  potassium  cyanide  solu¬ 
tion.  From  the  sheet  of  gold  connected  to  the  positive  pole  the 
gold  dissolves  off,  forming  potassium  aurocyanide.  The  action  of 
the  current  is  interrupted  when  the  solution  is  so  far  saturated  with 
gold  that  an  article  immersed  in  it  and  connected  to  the  negative 
pole  instead  of  the  other  gold-sheet,  is  gilded  with  a  beautiful  warm 
tone.  By  weighing  the  sheet  of  gold  serving  as  anode,  the  amount 
of  gold  which  has  passed  into  solution  is  ascertained.  A  good  gold 
bath  prepared  according  to  this  method  should  contain  3.52  ozs. 
of  potassium  cyanide  and  0.7  oz.  of  fine  gold  per  quart  of  water. 

As  anodes  it  is  best  to  use  sheets  of  fine  gold,  which  gradually 
dissolve,  and  thus  convey  fresh  metal  to  the  bath.  The  insoluble 
platinum  anodes  should  only  be  used  in  the  production  of  very  thin 
depositions.  The  color  of  the  gold  deposited  depends  on  the  con¬ 
tent  of  gold  of  the  bath,  its  temperature,  and  the  strength  of  the 
current.  Warm  baths  rich  in  gold  give  with  a  strong  current  a 
brown,  pulverulent  deposition  which,  though  it  becomes  bright  by 
scratch-brushing,  parts  with  gold.  Hence  the  use  of  a  current- 
regulator  is  of  great  advantage,  since  with  its  assistance  various 
shades  of  gold  color  can  be  obtained  in  one  bath.  It  may  be 
accepted  as  a  rule  that  the  stronger  the  current  the  more  reddish 
and  fiery  the  color  will  be,  and  the  weaker  the  current  the  paler 
and  more  greenish  the  color.  Electro-platers  of  the  old  school  use 
platinum  anodes  for  the  production  of  the  color,  allowing  them  to 
dip  in  more  or  less  deep ;  in  the  first  case  the  gilding  becomes 
more  reddish,  since  more  of  the  current  passes  into  the  bath,  and 
in  the  latter  paler. 


ELECTRO  PLATING,  BRASSING,  COPPERING,  ETC. 


341 


Only  copper,  brass,  bronze,  and  tombac  can  be  directly  gilded ; 
other  metals  must  first  be  coppered  or  brassed ;  cheap  steel  articles 
are  an  exception,  however ;  for  instance,  needles,  the  eyes  of 
which  may  be  directly  gilded.  Amalgamating  the  articles  before 
gilding  is  unnecessary.  The  current  must  not  be  so  strong  that  a 
formation  of  bubbles  is  perceptible,  as  otherwise  the  gold  would 
separate  brown  and  pulverulent ;  it  is  best  to  use  a  current  of  such 
strength  only  that  deposition  takes  place  slowly,  a  coating  of  the 
greatest  density  being  thus  obtained.  For  the  production  of  a  thick 
deposit  frequent  scratch-brushing  of  the  articles  is  absolutely  neces¬ 
sary,  the  brush  being  moistened  with  decoction  of  soap-root  or 
solution  of  tartar.  To  obtain  red  gold  a  copper  salt  has  to  be 
added  to  the  gold  bath,  it  being  best  to  use  solution  of  copper 
cyanide  in  potassium  cyanide,  small  portions  of  which  are  gradually 
added  until  the  desired  tone  of  red  gold  is  obtained ;  a  gold  bath 
may  also  be  converted  into  a  red  gold  bath  by  suspending  a  few 
copper  anodes  alongside  of  the  gold  anodes. 

Green  gold  is  obtained  by  the  addition  of  silver  solution,  cyanide 
or  chloride  of  silver  dissolved  in  potassium  cyanide ;  or  by  sus¬ 
pending  a  few  silver  anodes  alongside  the  gold  anodes,  whereby 
strict  attention  must  be  paid  to  the  careful  regulation  of  the 
current. 

Gilding  with  a  Dead  Lustre  may  be  effected  by  the  slow  deposit 
of  a  large  proportion  of  gold.  This  gilding  is  very  durable,  but 
dull  and  earthy  in  appearance  and  is  costly.  Other  means  of  ef¬ 
fecting  the  same  purpose  are  :  i.  By  acids ,  giving  a  dead  lustre  to 
the  metallic  surface,  previous  to  gilding,  and  by  the  processes  in¬ 
dicated  in  the  cleansing  operations.  This  is  employed  for  small 
articles,  or,  when  gilding  by  dipping,  for  brass  articles,  or  large 
embossed  work.  2.  With  frosted  silver,  by  depositing  upon  the 
object  to  be  gilt  a  coat  of  frosted  silver  and  then  gilding  in  a  good 
bath;  this  method  is  expensive,  the  burnished  parts  are  greenish, 
and  the  intermediary  coat  of  silver  is  more  easily  blackened  by 
sulphur  fumes  than  gold.  3.  By  copper,  by  depositing  in  a  solu¬ 
tion  of  sulphate  of  copper,  decomposed  by  the  current,  a  coat  of 
this  metal,  which  possesses  a  pink  dead  lustre.  The  whole  is 


342 


THE  METAL  WORKER’S  HANDY-BOOK. 


rapidly  passed  through  the  acid  mixture  for  bright  dipping  and 
then  gilded  in  a  good  bath. 

The  deposits  of  gold  are  frequently  further  colored  in  case  they 
have  not  acquired  the  right  tone  in  the  bath.  This  is  effected  by 
treating  them  with  gilders’  wax  or  brushing  with  certain  mixtures. 

Treatment  with  gilders’  wax  consists  in  uniformly  coating  the 
gilt  articles  with  the  wax  and  burning  it  off  over  a  charcoal  fire. 
The  articles  are  then  dipped  in  water,  scratch-brushed  with  wine- 
vinegar,  dried  and  burnished.  (For  various  compositions  of 
Gilders’  Wax  see  under  that  head.) 

To  give  the  articles  a  rich  appearance  they  may  be  coated  with 
a  paste  of  3  parts  alum,  6  parts  saltpetre,  3  parts  sulphate  of  zinc, 
3  parts  of  common  salt  and  water,  heating  until  the  mixture  turns 
black,  washing  and  scratch-brushing  with  wine-vinegar. 

Gilding  by  Contact  and  Dipping ,  Cold  Gilding  and  Gilding  by 
Adhesion. — The  article  is  first  pickled  and  must  not  again  be 
touched  with  the  hands.  It  is  then  placed  in  a  solution  of  gold 
and  touched  with  a  rod  of  zinc  or  copper,  whereby  metallic  gold  is 
precipitated  upon  the  article;  by  a  shorter  or  longer  contact  dif¬ 
ferent  colors  may  be  produced.  Gold  solutions  of  varying  composi¬ 
tion  are  employed  for  gilding  by  contact,  the  following  solution 
being,  for  instance,  used  for  jewelry.  Prepare  first  a  gold  solution 
by  dissolving  3.52  ozs.  of  fine  gold  in  a  mixture  of  8.81  ozs.  of 
nitric  acid  and  a  like  quantity  of  hydrochloric  acid  in  a  glass  or 
porcelain  vessel,  which  is  allowed  to  stand  a  few  days  in  a  warm 
place.  To  promote  dissolution  it  is  best  to  use  the  gold  in  the 
form  of  thin  sheet  or  wire,  thick  pieces  dissolving  very  slowly. 
The  clear  gold  solution  is  then  gradually  mixed  with  6.6  lbs.  of 
bicarbonate  of  potash,  whereby  it  strongly  effervesces,  and  the 
whole  is  then  poured  into  an  iron  kettle  containing  20  quarts  of 
boiling  water.  The  articles  to  be  gilded  being  again  pickled  with 
sulphuric  acid  are  then  tied  together  with  brass  wire,  again  dipped 
for  a  moment  in  a  mixture  of  nitric  and  hydrochloric  acids,  rinsed 
and  then  immediately  immersed  in  a  mercury  solution  prepared  by 
dissolving  mercury  in  nitric  acid  and  diluting  the  solution  with 
water.  In  case  the  articles  contain  much  copper  they  quickly  ac- 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


343 


quire  a  white  color  in  the  mercury  solution  by  becoming  coated 
with  a  thin  layer  of  mercury.  They  are  then  placed  in  the  gold 
bath  and  touched  with  a  zinc  rod.  After  remaining  in  the  gold 
bath  for  about  half  a  minute  they  are  taken  out,  rinsed  off  and 
dried.  The  rinsing  water,  which  contains  gold,  is  collected  and 
the  gold  regained  by  acidulating  the  water  with  hydrochloric  acid 
and  pouring  into  it  a  solution  of  ferrous  sulphate  (copperas), 
whereby  the  fluid  acquires  an  inky  appearance,  but  soon  again  be¬ 
comes  clear.  On  the  bottom  of  the  vessel  will  then  be  found  a 
very  fine  brown  powder,  which  consists  of  chemically  pure  gold 
and  can  be  again  used  for  the  preparation  of  gilding  fluid.  By 
sufficiently  heating  the  baths  the  following  formula  may  also  be 
advantageously  used  for  gilding  by  touching  with  a  zinc  rod : 

I.  Fine  gold  (in  the  form  of  fulminating  gold)  0.56  drachm  ; 
98  per  cent,  cyanide  of  potash,  2.82  drachms;  water,  1  quart. 
The  bath  is  prepared  by  converting  0.56  drachm  of  fine  gold  into 
neutral  chloride  of  gold  by  dissolving  in  aqua  regia  and  evaporat¬ 
ing;  or,  0.67  to  0.7  oz,  of  neutral  chemically  pure  chloride  of  gold 
is  dissolved  in  water,  the  gold  precipitated  as  fulminating  gold  with 
liquid  ammonia  and  washed.  It  is  then  dissolved  in  the  water 
containing  the  cyanide  of  potash  and  heated  until  the  odor  of  am¬ 
monia  disappears,  the  water  lost  by  evaporation  being  constantly 
replaced.  The  temperature  of  the  bath  should  be  about  158°  to 
167°  F.  If  necessary  the  amount  of  cyanide  of  potash  may  be 
increased. 

II.  Chemically  pure  crystallized  sodium  phosphate,  2.J1  ozs.  ; 
neutral  sodium  sulphate,  5.64  drachms;  cyanide  of  potash,  1.12 
drachms;  fine  gold  (in  the  form  of  chloride),  0.56  drachm;  dis¬ 
tilled  water,  1  quart.  If  this  bath  is  to  be  used  for  the  direct  gild¬ 
ing  of  steel  only  0.56  drachm  of  cyanide  of  potash  need  to  be 
taken.  Dissolve  at  a  moderate  heat  in  a  porcelain  or  enamelled 
iron  vessel  the  sodium  phosphate  and  neutral  sodium  sulphate,  and 
to  the  perfectly  cold  solution  add  the  neutral  gold  chloride  pre¬ 
pared  from  0.56  drachm  of  gold  and  the  cyanide  of  potash.  For 
use  heat  the  bath  to  from  158°  to  167°  F. 

III.  The  following  bath  yields  a  good  deposit :  Fine  gold  (in  the 


344 


THE  METAL  WORKER’S  IIANDY-ROOK. 


form  of  chloride  of  gold),  1.97  drachms;  yellow  prussiate  of 
potash,  1  oz.  ;  potash,  1  oz.  ;  common  salt,  1  oz.  ;  water,  1  quart. 
To  prepare  the  bath  heat  the  solution  of  the  yellow  prussiate  of 
potash,  potash  and  common  salt  in  the  water  to  the  boiling  point, 
add  the  gold  salt  and  boil  hour.  After  cooling  the  solution  is 
compounded  with  the  quantity  of  distilled  water  corresponding  to 
that  lost  by  evaporation,  and  filtered.  For  use  heat  the  bath  to 
the  boiling  point. 

In  the  execution  of  gilding  by  contact  the  points  of  contact 
must  be  frequently  changed  to  prevent  stains. 

For  Baths  for  Gilding  by  Dipping  the  following  two  formula 
have  stood  the  test.  I.  Crystallized  sodium  pyrophosphate,  2.82 
ozs. ;  12  per  cent,  prussic  acid,  4.51  drachms;  crystallized  chloride 
of  gold,  1. 12  drachms;  water,  1  quart.  Heat  the  bath  to  the 
boiling  point  and  immerse  the  pickled  objects  of  copper  or  its  al¬ 
loys,  moving  them  constantly,  until  gilded.  Iron,  steel,  tin  and 
zinc  are  previously  coppered,  coating  the  articles  with  mercury  be¬ 
fore  immersion  being  entirely  superfluous. 

All  gold  baths  prepared  with  sodium  pyrophosphate  give  quick 
and  beautiful  results  when  fresh,  but  they  have  the  disadvantage  of 
quickly  decomposing  and  can  consequently  seldom  be  completely 
utilized.  In  this  respect  the  following  formula  answers  much 
better : 

II.  Crystallized  sodium  phosphate,  2.82  drachms;  chemically 
pure  caustic  potash,  1.69  drachms;  chlcride  of  gold,  0.56  drachm; 
98  percent,  cyanide  of  potassium,  9.03  drachms;  water,  1  quart. 
Dissolve  the  sodium  phosphate  and  caustic  potash  in  ^  of  the 
water  and  the  cyanide  of  potash  and  chloride  of  gold  in  the  re¬ 
maining  Heat  the  solution  to  the  boiling  point;  the  bath 

can  be  almost  entirely  utilized,  it  not  being  decomposed  by  keep¬ 
ing.  Should  the  bath  become  weak  add  about  2.82  drachms  of 
cyanide  of  potash  and  use  it  for  preparatory  boiling  until  no  more 
separation  of  gold  is  obtained.  To  complete  the  coating  the  ar¬ 
ticles  subjected  to  such  preparatory  boiling  are  then  dipped  for  a 
few  seconds  in  a  freshly  prepared  bath  of  the  composition  given 
above. 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


345 


The  layer  of  gold  formed  by  dipping  is  in  all  cases  very  thin, 
the  amount  of  gold  precipitated  corresponding  with  the  quantity 
of  the  metal  forming  the  base  which  has  been  dissolved. 

Cold  Gilding,  or  Gilding  by  the  Rag. — This  mode  of  gilding  is 
chiefly  employed  upon  silver,  though  sometimes  also  upon  brass 
and  copper.  The  operation  is  as  follows :  Dissolve  1.12  or  1.69 
drachms  of  chloride  of  gold  in  as  little  water  as  possible,  to  which 
has  previously  been  added  0.56  drachm  of  saltpetre.  Dip  in  this 
solution  small  linen  rags  and,  after  allowing  them  to  dry  off,  dry 
them  in  a  dark  place.  These  rags  saturated  with  gold  solution  are 
then  charred  to  tinder  at  not  too  great  a  heat,  whereby  the  chloride 
of  gold  is  reduced,  partially  to  protochloride  and  partially  to  finely 
divided  metallic  gold.  This  tinder  is  then  rubbed  in  a  porcelain 
mortar  to  a  fine  uniform  powder. 

To  gild  with  this  powder  dip  into  it  a  charred  cork  moistened 
with  vinegar  or  salt  water  and  rub,  with  not  too  gentle  a  pressure, 
the  surfaces  of  the  article  to  be  gilded,  which  must  be  previously 
cleaned  from  adhering  grease.  The  thumb  of  the  hand  may  be 
used  in  place  of  the  cork  ;  but  in  both  cases  care  must  be  had  not 
to  moisten  them  too  much,  as  otherwise  the  powder  takes  badly. 
After  gilding  the  surface  may  be  carefully  polished  with  the  steel. 

For  cold  gilding  a  solution  of  chloride  of  gold  in  an  excess  of 
cyanide  of  potash  may  also  be  used,  after  thickening  the  solution 
to  a  paste  by  rubbing  in  whiting.  After  zincking  the  metals  the 
paste  is  applied  by  means  of  a  cork,  a  piece  of  leather  or  a  brush. 
Martin  and  Peyraud,  the  originators  of  this  method,  describe  the 
operation  as  follows :  Articles  of  other  metals  than  zinc  are  placed 
in  a  bath  consisting  of  a  concentrated  solution  of  sal-ammoniac, 
in  which  has  been  placed  a  quantity  of  granulated  zinc.  The  ar¬ 
ticles  are  allowed  to  boil  a  few  minutes,  whereby  they  acquire  a 
coating  of  zinc.  For  the  preparation  of  the  gilding  composition 
dissolve  11.28  drachms  of  chloride  of  gold  in  a  like  quantity  of 
water  and  add  a  solution  of  2.11  ozs.  of  cyanide  of  potash  in  as 
little  water  as  possible  (about  2.82  ozs.).  Of  this  solution  add  so 
much  to  a  mixture  of  3.52  ozs.  of  fine  whiting  and  2.82  drachms 
of  pulverized  tartar  that  a  paste  is  formed  which  can  be  readily  ap- 


346 


THE  METAL  WORKER’S  HANDY-ROOK. 


plied  with  a  brush  to  the  article  to  be  gilded.  When  the  article  is 
coated  heat  it  to  between  140°  and  158°  F.  After  removing  the 
dry  paste  by  washing  the  gilding  appears  and  can  be  polished  with 
the  burnishing-stone. 

To  Gild  by  Adhesion. — This  process  is  chiefly  employed  upon 
sword-blades,  gun-barrels  and  similar  objects  which  are  to  be  pro¬ 
vided  with  gilded  decorations.  For  this  purpose  the  finely- 
polished  article  is  coated  with  an  etching  ground  prepared  by  melt¬ 
ing  together  equal  parts  of  resin,  wax  and  black  pitch  and  adding  to 
the  melted  mass  x  parts  of  asphalt  and  \l/2  parts  of  mastic.  The 
desired  design  is  then  scratched  in  the  etching  ground  and,  after 
roughening  the  portions  thus  exposed  with  nitric  acid  and  rinsing 
in  water,  the  etching  ground  is  removed  with  oil  of  turpentine. 
The  object  is  then  heated  until  it  acquires  a  blue  color,  and  a 
double  layer  of  gold-leaf  is  then  laid  on  the  roughened  portions 
and  pressed  down  with  the  burnisher.  As  many  gold  leaves  as  de¬ 
sired  may  in  this  manner  be  laid  on,  but  every  two  leaves  must  be 
burnished.  Instead  of  roughening  the  portions  to  be  gilded  by 
etching  with  acid,  the  design  is  frequently  scratched  in  the  object 
with  a  sharp  tool  and  the  gold  made  to  adhere  in  the  manner  de¬ 
scribed  above  by  pressing  and  burnishing.  This  method  requires, 
however,  more  gold  than  the  first. 

To  Gild  Steel. — Steel  is  best  gilded  as  follows  :  Dissolve  chloride 
of  gold  free  from  acid,  in  water,  add  three  times  the  volume  of  the 
solution,  of  ether,  and  after  24  hours  lift  off  the  ethereal  gold  solu¬ 
tion.  Polished  steel  dipped  in  this  solution  is  immediately  beauti¬ 
fully  gilded.  By  coating  portions  of  the  steel  with  lacquer  or 
varnish  beautiful  designs  can  be  produced.  For  other  metals  than 
steel,  gilding  by  the  galvanic  process  is  to  be  preferred. 

To  Fire-gild  Silver  Objects. — Wrap  several  pieces  of  leaf-gold 
around  a  round  cylindrical  rod  of  silver,  wrap  the  whole  in  paper, 
and,  after  securing  it  with  thread  or  twine,  heat  it  in  a  coal  fire. 
The  twine  and  paper,  of  course,  char,  but  the  gold  at  the  same  time 
unites  firmly  with  the  silver.  The  union  of  the  metals  may  be  still 
further  increased  by  polishing  with  the  burnisher  or  a  burnishing- 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


347 


stone  of  blood-stone.  The  rod  of  silver  thus  gilded  can  be  drawn 
out  to  the  finest  wire. 

To  Fire-gild  and  Fire-silver  Metals  which  Cannot  be  Amalga¬ 
mated ;  for  Instance,  Iron  and  Steel. — First  copper  the  objects,  and 
then  gild  or  silver  in  the  usual  manner  with  gold  or  silver  amalgam. 
If  damaskeening  in  gold  or  silver  upon  an  iron  or  steel  ground  or  vice  ‘ 
versa  is  to  be  produced,  the  entire  surface  is  first  coppered.  The 
places  which  are  to  be  silvered  or  gilded  are  then  coated  with 
asphalt  lacquer,  and  the  article  is  dipped  in  solution  of  chromic 
acid,  which  dissolves  the  copper  unprotected  by  the  varnish,  and 
leaves  the  iron  or  steel,  which  is  not  attacked  by  it,  exposed.  The 
varnish  is  then  removed  with  oil  of  turpentine,  and  the  gilding  or 
silvering  executed  in  the  usual  manner  upon  the  coppered  portion. 
For  platinum  the  process  is  the  same,  but  nitric  acid  is  used  instead 
of  chromic  acid. 

To  Give  Gilt  Articles  a  Beautiful  Rich  Appearance. — Pulverize 
and  mix  alum,  3  parts  by  weight ;  nitrate  of  potash,  6  ;  sulphate  of 
zinc,  3 ;  and  common  salt,  3,  with  sufficient  water  to  form  a  thinly 
fluid  paste.  Apply  this  paste  as  uniformly  as  possible  to  the  objects 
by  means  of  a  brush,  and  when  dry  heat  them  upon  a  hot  iron 
plate  until  the  coating  becomes  black.  Then  wash  in  water, 
scratch-brush  with  wine-vinegar,  dry,  and  polish. 

According  to  a  French  direction,  the  same  result  is  attained  by 
pulverizing  and  mixing  sulphate  of  copper  (blue  vitriol),  3  parts  by 
weight;  verdigris,  7;  sal-ammoniac,  6;  nitrate  of  potash,  6,  with 
acetic  acid,  31  ;  dipping  the  gilt  articles  into  the  mixture,  heating 
upon  an  iron  plate  until  black,  and,  when  cold,  pickling  with  con¬ 
centrated  sulphuric  acid. 

Some  practitioners  unprove  bad  tints  of  gilding  by  dipping  the 
objects  into  a  dilute  solution  of  nitrate  of  mercury  until  the  gilding 
shows  a  white  amalgam ;  the  mercury  is  then  volatilized  over  a 
flame,  and  the  object  scratch-brushed.  Others  apply  a  paste  of 
pulverized  borax  and  water,  heat  until  the  borax  melts,  and  then 
dip  quickly  in  dilute  sulphuric  acid. 

To  Gild  Articles  of  Metal. — The  following  process  has  been 
patented  in  Germany  :  A  solution  of  aluminium  nitrate  and  cobalt- 


348 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


ous  nitrate  is  evaporated  and  glowed.  Of  the  residue  21.16  ozs.  are 
melted  together  with  122.96  ozs.  of  red-lead,  28.21  ozs.  of  boric 
acid,  and  7.05  ozs.  of  glass  powder,  pulverized  finely  and  rubbed 
up  with  oil  of  turpentine.  An  acid  solution  of  3.52  ozs.  of  gold  is 
mixed  with  30.86  grains  of  tin  and  a  like  quantity  of  arsenious 
acid,  and  any  acid  present  neutralized  with  ammonia.  The  objects 
to  be  gilded  are  first  coated  with  the  above-mentioned  enamel  and 
burnt,  and  then  brushed  with  the  gilding  fluid  and  again  burnt. 

Imitation  Gilding. — A  very  beautiful  coating  upon  copper  is 
obtained  by  boiling  the  objects,  previously  pickled  very  bright,  in 
very  dilute  hydrochloric  acid,  to  which  have  been  added  tartar  and 
an  amalgam  of  1  part  zinc  and  12  parts  of  mercury.  The  articles, 
after  being  washed  and  dried,  are  heated  to  volatilize  the  mercury, 
and  a  gold-colored  precipitate  capable  of  taking  a  high  polish  will 
appear. 

Gilding  Powder  for  Copper ,  Silver,  Brass,  etc. — Mix  proto¬ 
chloride  of  gold,  20  parts;  cyanide  of  potash,  60;  distilled  water, 
100;  tartar,  5  ;  and  finely  elutriated  chalk,  100.  By  means  of  a 
clean  woollen  rag  apply  this  mixture  to  the  article  to  be  gilded, 
which  should  previously  be  cleaned  and  drawn  through  a  pickle  of 
a  mineral  acid. 

Gilder' s  Wax  for  Fire-gilding. — The  wax  used  in  fire-gilding 
serves  for  coloring  the  gold,  and  consists  of  an  intimate  mixture 
of  yellow  wax  with  finely  pulverized  verdigris,  to  which,  as  a  rule, 
some  bole,  burnt  alum  or  burnt  borax  is  added.  The  theory  of 
the  use  of  gilder’s  wax  is  as  follows :  By  the  verdigris  (cupric 
acetate)  an  actual  red  alloy  is  produced  upon  the  surface  of  the 
article  to  be  gilded.  This  is  effected,  1,  by  the  precipitation  of 
copper  from  the  melting  mixture  upon  the  zinc  of  the  bronze ;  2, 
by  the  co-operation  of  the  products  of  the  dry  distillation  of  the 
wax  and  the  acetic  acid,  the  heated  cupric  oxide  of  the  verdigris  is 
reduced  to  copper  which,  as  well  as  the  copper  precipitated  upon 
the  zinc,  combines  with  the  gold  to  a  reddish  gold  alloy.  The 
remaining  ingredients  serve  only  for  the  dilution  of  the  active 
copper  combinations,  though  some  gilders  claim  to  have  observed 
that  gilder’s  wax  containing  alum  gives  a  lighter  color  than  that 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


349 


prepared  with  borax.  Hence  it  is  possible  that  in  using  gilder’s 
wax  containing  alum  an  alloy  of  gold  and  aluminium  is  produced. 
For  preparing  gilder’s  wax  there  are  a  number  of  directions,  of 
which  those  which  have  stood  the  test  are  here  given.  For  all  kinds 
of  gilder’s  wax  the  separate  constituents  are  pulverized  and  passed 
through  a  fine  hair-sieve ;  the  particles  remaining  in  the  sieve 
being  further  pulverized  until  all  has  passed  through.  The 
pulverized  ingredients  are  then  mixed,  care  being  had  to  inhale  as 
little  as  possible  since  verdigris  is  poisonous.  Melt  the  wax  in  a 
clean  pot,  without,  however,  allowing  it  to  become  too  hot,  and 
gradually  add  the  ingredients  with  constant  stirring  to  prevent  the 
heavier  metallic  particles  from  settling  on  the  bottom.  Then  pour 
the  mass,  with  constant  stirring,  into  a  suitable  vessel,  previously 
cooled  and  moistened  with  water,  and  after  cooling  cut  it  up  into 
pieces. 

I.  White  wax,  8  parts;  verdigris,  2;  cupric  sulphate  (blue 
vitriol),  2;  borax, 

II.  White  wax,  12  parts;  Armenian  bole,  3;  verdigris,  ij4‘, 
ferric  sulphate,  2;  burnt  ochre,  ;  and  borax, 

III.  White  wax,  12  parts;  verdigris,  >  copper-scales,  3;  and 
borax, 

IV.  Yellow  wax,  18  parts;  red  chalk,  8;  cupreous  water,  3; 
verdigris,  2 ;  borax,  1  y2  ;  and  burnt  copper,  3. 

V.  Yellow  wax,  18  parts;  verdigris,  6;  sulphate  of  zinc,  6 ;  red 
chalk,  8}^  ;  copper  scales,  4 ;  ferrous  sulphate  (copperas),  3  ;  col- 
cothar,  j  and  borax, 

Quicksilver  Water  is  a  solution  of  mercurous  nitrate,  and  is 
prepared  by  dissolving  10  parts  of  metallic  mercury  in  xi  of  cold 
nitric  acid  of  36°  B.,  and  diluting  the  solution  with  275  parts  of 
rain  or  distilled  water.  It  serves  for  moistening  bronze  as  well 
as  copper,  brass  and  German  silver,  and  even  silver  of  less  fine¬ 
ness  than  -pj5<j0o,  which  do  not  take  the  gold  amalgam  well  before 
gilding. 

Iron-baths. — Depositions  of  iron  serve  chiefly  for  coating,  or  so- 
called  steeling,  of  copper-plates,  cliches,  etc.,  to  make  them  more 
capable  of  resisting  mechanical  wear.  Galvanically  precipitated 


350 


THE  METAL  WORKER’S  HANDY-BOOK. 


iron  is  extraordinarily  hard,  but  also  very  brittle,  and  hence  thick 
depositions  are  difficult  to  obtain.  Moreover,  in  modern  times 
nickelling  the  plates  has  been  successfully  substituted  for  steeling. 

According  to  Varrentrap  the  following  bath  serves  for  steeling: 
Pure  green  vitriol,  4.75  ozs.;  sal-ammoniac,  3.5  ozs.  ;  water,  1 
quart.  Boil  the  water  for  y,  hour  to  remove  all  air,  and  after 
cooling  add  the  green  vitriol  and  sal-ammoniac.  By  the  action  of 
the  air  this  bath  separates  ferric  hydrate  in  flakes,  and  it  must, 
therefore,  be  frequently  filtered.  It  requires  a  current  of  1  to  1.25 
volts.  To  decrease  the  tendency  of  the  bath  to  decompose,  am- 
monio-ferrous  sulphate  may  be  used. 

A  simple  solution  of  sal-ammoniac  (3. 50  ozs.  of  sal-ammoniac 
to  1  quart  of  water)  may  also  be  made  into  an  iron-bath  by  hang¬ 
ing  in  iron  sheets  as  anodes,  suspending  a  copper-plate  to  the 
negative  pole  and  allowing  the  current  to  circulate  until  a  regular 
separation  of  iron  is  attained,  which  is  generally  the  case  in  5  to 
6  hours. 

For  decorative  purposes  a  deep-black  deposition  of  iron  may  be 
produced  as  follows:  Dissolve  as  large  a  quantity  of  steel-filings  as 
possible  in  50  quarts  of  commercial  hydrochloric  acid.  The  satu¬ 
ration  of  the  solution  is  recognized  by  a  sediment,  which  no  longer 
dissolves,  being  formed  on  the  bottom  of  the  vessel.  Then  add  2 
lbs.  of  white  arsenic  and  vigorously  stir  the  mixture.  The  arsenic 
dissolves  very  slowly;  but  the  bath  cannot  be  considered  finished 
until  all  of  it  is  dissolved,  and  the  color  obtained  by  means 
of  the  bath  is  the  deeper  the  more  complete  the  solution  of  the 
arsenic.  The  articles  to  be  treated  are  connected  to  the  negative 
pole  of  the  battery,  iron  and  carbon-plates  serving  as  anodes.  For 
a  bath  of  50  quarts  two  Bunsen  elements  about  7^  inches  high 
are  required,  and  the  bath  being  very  acid  the  articles  must  be 
connected  with  the  battery  previous  to  immersion.  Upon  copper 
and  brass  the  deposit  is  directly  produced,  but  iron  articles  being 
attacked  by  the  bath  are  first  provided  with  a  coat  of  nickel.  The 
deposit  of  iron  upon  this  nickel  coating  is  very  beautiful,  and  has 
been  designated  by  the  name  of  “  black  nickelling.” 

A  steel  bath  recommended  by  Klein  as  doing  good  service  con- 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


351 


sists  of  a  solution  of  equal  parts  of  green  vitriol  and  of  sulphate 
of  magnesia.  The  solution  is  kept  neutral  by  suspending  in  it 
bags  filled  with  carbonate  of  magnesia.  The  most  suitable  con¬ 
centration  of  the  solution  corresponds  to  a  specific  gravity  of  1.55, 
and,  according  to  recent  experiments,  the  density  of  current 
should  at  the  utmost  amount  to  0.02  ampere  per  61  cubic  inches. 

Lead-baihs. — Dissolve  by  continued  boiling,  caustic  potash,  x .  75 
ozs.  and  finely  pulverized  litharge,  0.17  ozs.  in  x  quart  of  water. 
According  to  Watt  the  following  solution  is  used  :  Acetate  of  lead, 
0.17  oz.  ;  acetic  acid,  o  17  oz.  ;  water,  1  quart.  The  bath  pre¬ 
pared  according  to  the  first  formula  deserves  the  preference. 

Lead  baths  require  anodes  of  sheet-lead  or  cast-lead  plates,  a 
weak  current,  and  frequent  scratch-brushing  of  the  articles  in  order 
to  make  the  deposition  more  dense  and  to  attain  greater  thickness. 
Iron  is  best  first  coppered.  Superoxide  of  lead  being  separated 
upon  the  anodes,  the  latter  must  be  frequently  cleansed  with  the 
scratch-brush. 

To  Coat  Metals  with  Lead. — A  coat  of  lead  protects  metals  from 
the  effects  of  mineral  acids  and  other  chemical  products,  and, 
hence,  vessels  of  lead  or  of  leaded  metal  are  much  used 
in  the  chemical  industries.  Lead  possesses,  however,  but  little 
solidity  and  power  of  resistance,  and  apparatus,  which  has  to  resist 
a  certain  pressure,  such  as  evaporating  pans,  crystallizing  vessels, 
acid  reservoirs,  monte-jus,  and,  in  general,  apparatus  for  acid  fluids 
and  gases,  is  seldom  made  of  it,  that  manufactured  from  leaded 
sheet-iron  or  sheet-copper  being  more  durable.  In  a  galvanic  man¬ 
ner  lead  coatings  can  only  be  produced  by  means  of  a  bath,  which 
consists  of  a  solution  of  oxide  of  lead  in  caustic  potash  or  caustic 
soda.  The  fluid  is  prepared  as  follows:  Dissolve  1  part  of  purified 
potash  in  10  to  12  parts  of  water,  and  gradually  add  1  part  of  burnt 
lime  in  the  form  of  powder.  To  test  whether  the  potash  has  been 
completely  converted  into  caustic  potash,  mix  a  small  sample  of  the 
fluid  with  dilute  sulphuric  acid.  If  no  effervescence  takes  place  the 
conversion  is  complete.  Now  separate  the  precipitate,  which  con¬ 
sists  of  carbonate  of  lime,  from  the  caustic  potash  lye  by  filtering 
through  strong  linen.  Then  boil  the  lye  in  an  iron  kettle  until  it 


352 


THE  METAL  WORKER’S  HANDY-BOOK. 


shows  a  specific  gravity  of  1.33.  When  this  is  the  case  allow  the 
lye  to  cool  off,  and  then  preserve  it  for  future  use  in  well-corked 
bottles.  For  use  boil  litharge  in  the  lye  until  nothing  more  dis¬ 
solves,  and  into  this  fluid,  which  represents  the  lead  bath,  place  the 
object  to  be  leaded.  The  object  is  connected  to  the  cathode  of  the 
battery,  a  sheet  of  lead  serving  as  the  anode.  In  this  manner  all 
metals  can  be  provided  with  a  lead  coating.  It  is  best  to  previously 
copper  iron  in  the  galvanic  manner.  The  same  fluid  can  be  used 
for  leading  brass  and  copper  by  contact.  The  thoroughly  cleansed 
articles  are  suspended  in  the  solution  heated  to  the  boiling  point, 
and  touched  with  a  piece  of  tin.  The  articles  immediately  become 
coated  with  a  coherent  layer  of  lead,  while  the  tin  goes  into  solu¬ 
tion.  Coatings  of  lead  are,  however,  more  frequently  produced  in 
a  dry  way  than  by  leading  in  the  galvanic  manner  or  by  contact. 
The  pickled  sheets  are  dipped  in  a  solution  of  sal-ammoniac,  im¬ 
mediately  dried,  and  then  immersed  in  the  lead  bath.  Lead  not 
adhering  well,  especially  to  iron,  this  bath  seldom  consists  of  the 
pure  metal,  alloys  of  lead  and  tin,  of  tin,  lead,  and  antimony,  or 
of  lead  and  zinc  being  generally  used.  According  to  a  German 
patent,  the  metals  to  be  leaded  are  pickled  in  an  acid — for  iron  it 
is  best  to  use  dilute  hydrochloric  acid  containing  some  zinc  in 
solution — and  then  tinned  upon  one  side.  The  thoroughly  tinned, 
cleansed,  and  completely  dry  sheets  are  fixed  horizontally  with  a 
narrow  rim  or  border  of  sand  or  metal  around  them,  and  heated 
until  the  thin  layer  of  tin  upon  the  metal  melts.  Melted  lead  freed 
as  much  as  possible  from  oxide  is  then  poured  over  the  surface  of 
the  sheets.  The  lead  flows  over  the  metal,  and  forming  a  lead- 
tin  alloy  with  the  layer  of  tin,  coats  the  sheet  with  a  layer  of 
uniform  thickness.  A  principal  requisite  is  to  heat  the  sheets  to 
between  428°  and  4470  F.,  the  temperature  at  which  the  layer  of 
lead  commences  to  melt.  Small  irregularities  due  to  pouring  the 
metal  are  removed  by  hammering  or  passing  the  leaded  sheets 
through  an  ordinary  plate-roll.  Sheets  of  metal  prepared  in  this 
manner  can  be  bent,  rivetted,  and  hammered  without  causing  a 
separation  of  the  lead  from  the  other  metal. 

Improved  Method  of  Covering  Articles  of  Iron  with  Lead. — The 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


353 


article  of  iron  or  steel  is  first  cleaned  (preferably  by  steel  brushes), 
then  roughened  by  a  sand-jet  blower,  washed  over  with  a  soldering 
liquid,  and  plunged  into  a  bath  of  molten  lead.  While  in  the  bath 
the  article  is  brushed  with  steel  brushes  to  insure  intimate  contact 
between  the  lead  and  iron.  The  layer  of  lead  thus  obtained  is  too 
thin  to  protect  the  iron  from  the  action  of  acids,  and  the  article  is 
subjected  to  a  second  operation.  If  it  be  a  plate  of  iron  or  steel 
it  is  fixed  horizontally,  with  a  narrow  rim  or  border  placed  round 
it,  and  it  is  then  washed  over  with  a  soldering  liquid,  heated  to 
about  750°  F. ,  and  molten  lead  is  poured  over  its  surface  and 
uniformly  distributed.  The  height  of  the  rim  determines  the 
thickness  of  the  layer  of  lead.  The  whole  is  then  again  heated  to 
a  temperature  above  the  melting-point  of  lead,  and  the  surface 
again  brushed  with  steel  brushes.  The  plate  is  then  allowed  to 
cool,  care  being  taken  during  the  cooling  of  the  sheet-iron  or  plate 
to  keep  the  layer  of  lead  as  long  as  possible  above  the  melting-point 
of  lead  by  fresh  additions  of  small  quantities  of  molten  lead.  In 
the  case  of  pipes,  boilers,  or  similar  vessels,  a  suitable  “core”  or 
casing  is  provided,  and  after  treating  the  surface  with  soldering 
liquid  and  heating  to  75  20  F.,  the  space  between  the  article  and 
the  “core”  is  filled  with  molten  lead.  The  whole  is  then  again 
heated  above  the  melting-point  of  lead,  and  finally  allowed  to  cool 
slowly,  the  lead  again  being  kept  as  long  as  possible  in  a  molten 
state. 

Ley  son' s  Process  of  Leading. — The  iron,  sheet  or  wire,  is  first 
pickled  bright  with  acid,  then  brought  into  a  solution  of  sal- 
ammoniac,  and  dried.  The  melted  lead  is  in  an  iron  kettle  or  box, 
whose  upper  cross-section  is  separated  by  a  bridge-like  partition,  so 
that  it  dips  only  very  slightly  into  the  melted  lead.  The  lead  on 
one  side  of  this  partition  is  covered  with  sand,  while  on  the  other 
side  a  few  pieces  of  sal-ammoniac  are  thrown  upon  the  surface  to 
prevent  the  formation  of  oxide.  It  is  necessary  to  compound  the 
lead  with  some  zinc,  which  is  effected  by  stirring  about  every  half 
hour  with  a  zinc  rod  dipped  in  a  solution  of  sal-ammoniac,  whereby 
for  every  330  lbs.  of  lead  about  8.46  drachms  of  zinc  alloy  are 
added.  The  iron  sheets,  previously  pickled,  washed  in  solution  of 
23 


354 


THE  METAL  WORKER’S  HANDY-BOOK. 


sal-ammoniac,  and  quickly  dried  with  the  assistance  of  heat,  are 
then  immersed  in  the  lead  bath  prepared  in  the  manner  above 
described.  The  sheets  are  introduced  from  the  sal-ammoniac  side, 
carried  through  under  the  partition  by  means  of  tongs,  and  drawn 
out  through  the  layer  of  sand. 

Alloys  for  Hot  Leading. — I.  Lead,  9  parts;  tin,  1;  antimony, 

1.  Melt  under  a  cover  of  common  salt,  to  which  some  chloride  of 
barium  may  be  added.  The  pickled  sheets  of  iron  are  immersed  in 
the  melted  mixture. 

II.  Lead,  7  to  8  parts;  tin,  1  part;  this  alloy  may  be  improved 
and  made  more  durable  by  the  addition  of  some  zinc  and  anti¬ 
mony. 

III.  An  alloy  with  1  to  2  per  cent,  of  tin  and  6  per  cent,  of 
arsenic  is  claimed  to  adhere  well  to  iron,  but  on  account  of  its 
great  content  of  arsenic  it  could  only  be  used  in  very  few  cases. 

IV.  Tin,  3  parts;  lead,  16;  copper,  1 ;  and  antimony,  1  ;  or, 
tin,  3  parts  ;  and  lead,  17. 

Nickel  Baths. — The  extensive  application  of  nickel-plating  is 
due  to  the  elegant  appearance  of  the  plated  ware,  the  constancy 
of  nickel  when  exposed  to  atmospheric  influences,  its  hardness, 
and  the  ease  with  which  the  operation  is  executed. 

Preparation  of  the  Metals  to  be  Nickelled. — Iron  and  steel  are 
immersed  for  some  time  in  boiling  hot  solution  of  caustic  soda  or 
potash,  then  thoroughly  brushed,  rinsed  in  cold  water  and  finally 
dipped  in  an  acid  pickle  of  1  part  of  sulphuric  acid,  2  of  hydro- 
choloric  acid  and  10  of  water,  after  which  they  are  again  rinsed, 
thoroughly  rubbed  with  fine,  washed  pumice-stone  or  Vienna  lime, 
rinsed  off  and  at  once  brought  into  the  bath.  Fine  polished  in¬ 
struments  of  iron  and  steel  for  surgical,  dental  and  other  purposes, 
scissors,  knives  and  telegraph  instruments  are  treated  in  the  same 
manner,  but  in  place  of  the  washed  pumice-stone  they  should  be 
brushed  with  whiting  or  tripoli,  or,  what  is  still  better,  with  infu¬ 
sorial  earth.  Brass,  bronze,  Britannia  metal,  etc.,  are  also  treated 
with  a  hot  solution  of  caustic  soda  or  potash,  then  rubbed  and 
brushed,  rinsed  in  water  and  at  once  placed  in  a  solution  of  potas¬ 
sium  cyanide  in  water  (8*^  ozs.  of  potassium  cyanide  to  4  quarts 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


355 


of  water).  They  are  then  cleansed  with  a  bristle  brush  kept  for 
that  purpose,  carefully  rinsed  in  water  and  at  once  brought  into  the 
bath.  The  variegated  colors  produced  upon  brass  by  the  action  of 
the  solution  of  caustic  soda  disappear  almost  instantaneously  in  the 
solution  of  cyanide,  and  a  bright  surface  of  the  metal  is  sure  to  be 
obtained.  Special  attention  must  be  paid  to  the  careful  rinsing  of 
the  articles,  especially  if  they  have  hollow  places  and  depressions, 
after  they  have  been  treated  in  the  solution  of  cyanide  of  potas¬ 
sium,  to  prevent  the  nickel  bath  from  being  spoiled  by  the  cyanide. 
For  many  articles  of  brass  having  more  or  less  dull  and  finely 
polished  places  it  is  sufficient  to  dip  them,  after  having  been  freed 
from  all  fatty  substances  by  boiling  caustic  soda  lye  and  subsequent 
rinsing  in  water,  into  the  mixture  of  acids,  then  to  rinse  them 
again  and  bring  them  at  once  into  the  bath.  For  iron  castings  or 
filed  articles  the  use  of  finely-sifted  pumice  or  chalk  is  absolutely 
necessary.  Copper  wire  should  be  tightly  wound  around  all  metal¬ 
lic  articles  and  two  or  more  wires  around  large  articles.  With  ar¬ 
ticles  consisting  of  two  metals,  for  instance  iron  with  steel,  or  with 
brass,  the  wire  must  be  wound  around  both  metals.  Smaller 
articles  are  suspended  from  copper  hooks.  The  articles  should  not 
be  immersed  in  the  nickelling  bath  until  the  battery  or  dynamo  is 
in  action.  The  objects  remain  in  the  bath  until  they  have  acquired 
a  white  color,  which  will  require  from  5  to  30  minutes,  according 
to  the  strength  of  the  current  and  the  number  and  size  of  the 
articles  suspended.  Large  objects  of  steel  or  iron  require  longer 
than  brass,  copper,  etc.,  and,  if  they  fill  the  bath  entirely,  must 
remain  in  it,  according  to  circumstances,  for  several  hours  or  an 
entire  night.  In  case  the  article  to  be  nickelled  assumes  a  gray  or 
black  color,  or  feels  gritty  or  rough,  the  current  is  too  strong.  The 
appearance  of  a  yellowish  white  coloration  is  due  to  too  weak  a 
current.  The  article  after  its  removal  from  the  bath  should  im¬ 
mediately  be  dipped  for  a  few  seconds  in  boiling  water,  then 
allowed  to  drain  off,  dried  in  warm  saw-dust  free  from  rosin  and,  if 
necessary,  polished.  Fine  articles  are  rubbed  with  a  polishing 
brush  or  with  soft  leather  and  whiting.  Burnishing  the  nickelled 
articles  with  the  steel  is  not  admissible,  as  the  coating  is  too  hard 


356 


THE  METAL  WORKER’S  HANDY-BOOK. 


and  too  brittle  for  such  usage.  The  better  the  articles  have 
been  polished  before  plating  the  more  beautiful  the  nickelling 
will  be. 

The  composition  of  the  baths  depends  partially  on  the  nature  of 
the  metals  to  be  nickelled.  While  one  and  the  same  bath  may  be 
used  for  nickelling  all  kinds  of  metal,  some  compositions  offer 
greater  advantages  for  nickelling  certain  metals,  on  account  of  the 
greater  whiteness  of  the  deposit  obtained  and  the  weaker  current 
required,  etc.  It  is  always  best  to  use  several  baths  and  not  to 
nickel  all  kinds  of  metals  in  one  and  the  same  bath.  It  is,  for  in¬ 
stance,  entirely  wrong  to  nickel  zinc  articles,  even  when  previously 
coppered  in  a  bath  in  which  iron  and  brass  are  treated. 

A  further  requirement  in  nickelling  is  the  use  of  pure  nickel 
salts  free  from  other  metals;  the  anodes  must  also  be  made  of  pure 
nickel. 

Boric  acid,  recommended  by  Weston  as  an  addition  to  nickel 
baths,  as  well  as  to  other  galvanic  baths,  has  a  favorable  effect  upon 
the  pure,  white  separation  of  nickel,  especially  in  nickelling  un¬ 
ground  surfaces. 

The  most  Simple  Nickel  Bath  consists  of  a  solution  of  8  to  io 
parts  by  weight  of  pure  double  sulphate  of  nickel  and  ammonium 
in  ioo  parts  by  weight  of  distilled  water;  the  solution  if  too  acid 
is  neutralized  to  a  slightly  acid  reaction  with  spirits  of  sal-ammo¬ 
niac.  The  solution  is  prepared  by  boiling  the  salt  with  the  cor¬ 
responding  quantity  of  water,  using  in  summer  io  parts  of  nickel 
salt  to  ioo  of  water,  but  in  winter  only  8  parts,  to  prevent  the 
nickel  salt  from  crystallizing  out.  This  bath  requires  a  strong 
current  and  cast  nickel  anodes. 

Weston's  Solution. — Double  sulphate  of  nickel  and  ammonium, 
io  parts;  refined  boric  acid,  2^  to  5;  water,  150  to  200.  The 
nickel  salt  and  boric  acid  may  be  dissolved  separately  in  boiling 
water,  the  solutions  mixed  and  the  volume  brought  up  to  that  of 
the  formula,  or  the  two  components  may  be  dissolved  together. 

Pott's  Solution. — Acetate  of  nickel,  2 parts;  acetate  of  cal¬ 
cium,  2^/2  ;  water,  100.  To  each  gallon  of  this  solution  add  1  oz. 
acetic  acid  1.047  specific  gravity. 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


357 


To  prepare  this  bath  dissolve  about  the  same  quantity  of  the  dry 
carbonate  of  nickel  as  that  called  for  in  the  formula  (or  three- 
quarters  of  that  quantity  of  the  hydrated  oxide)  in  acetic  acid, 
adding  the  acid  cautiously  and  heating  until  effervescence  has 
ceased,  and  solution  is  complete.  The  acetate  of  calcium  may  be 
made  by  dissolving  the  same  weight  of  carbonate  of  calcium  (mar¬ 
ble  dust)  as  that  called  for  in  the  formula  (or  one-half  that  quan¬ 
tity  of  caustic  lime)  and  treating  it  in  the  same  manner.  Add  the 
two  solutions  together,  dilute  the  volume  to  the  required  amount 
by  the  addition  of  water,  and  then  to  each  gallon  of  the  solution 
add  i  oz.  of  free  acetic  acid. 

Powell's  Solutions. — I.  Sulphate  of  nickel,  6  parts;  citrate 
of  nickel,  3;  phosphate  of  nickel,  3;  benzoic  acid,  ij4;  water, 
200. 

II.  Phosphate  of  nickel,  10  parts  ;  citrate  of  nickel,  6 ;  pyro¬ 
phosphate  of  sodium,  10;  bisulphide  of  sodium,  1  y2  ;  citric  acid, 
3;  aqua  ammonia,  15  ;  water,  400.  These  solutions  yield  good 
results,  but  their  complex  composition  must  debar  them  from 
general  use. 

The  following  bath  is  much  used  in  this  country,  and  is  especially 
suitable  for  nickelling  ground  surgical  instruments,  as  well  as  all 
ground  iron  articles  which  are  to  be  thickly  and  solidly  nickelled. 
It  is  also  excellent  for  solid  nickelling  of  copper,  brass  and  bronze. 
The  deposit  of  nickel  is  white,  dense  and  hard,  and  hence  takes 
a  high  polish  without  danger  of  the  nickel  grinding  off.  The  bath 
is  prepared  by  dissolving  the  salts  in  boiling  water,  and  when  cool 
adding  small  fragments  of  ammonium  carbonate  until  the  bath  is 
neutral  to  test-paper.  It  is  composed  of  sulphate  of  nickel  and 
ammonium,  25)4  ozs,  ;  ammonium  sulphate,  7.9  ozs.  ;  crystallized 
citric  acid,  1^  oz.  ;  water,  10  to  12  quarts.  It  requires  a  current 
of  2  to  2.2  volts. 

Baths  for  Rapidly  Nickelling  Cheap  Articles. — I.  Chloride  of 
nickel  and  sal-ammoniac  each,  1.75  ozs.  ;  water,  1  quart;  or,  II. 
Sulphate  of  nickel  and  ammonium,  2  ozs.  ;  sal-ammoniac,  1  oz.  ; 
and  water,  1  quart.  If  too  acid,  neutralize  both  solutions  with 


358 


THE  METAL  WORKER’S  HANDY-BOOK. 


spirits  of  sal-ammoniac.  The  bath  prepared  with  chloride  of  nickel 
is  preferably  used  for  nickelling  zinc  lamps. 

Nickel  Baths  for  Special  Purposes. — I.  Sulphate  of  nickel  and 
ammonium,  ioj4  ozs.  ;  potassium  citrate,  7  ozs.  ;  ammonium 
chloride,  io}4  ozs.  ;  water,  10  to  12  quarts.  To  prepare  the  bath 
dissolve  10  ozs.  of  nickel  sulphate  and  3^2  ozs.  of  pure  crystallized 
citric  acid  in  water,  neutralize  accurately  with  caustic  potash  and 
then  add  the  ammonium  chloride.  This  bath  is  especially  adapted 
for  quick  nickelling  of  polished  zinc  wares  previously  slightly 
coppered.  The  deposition  is  effected  with  a  very  feeble  current 
without  the  formation  of  black  streaks  such  as  otherwise  are  apt  to 
appear  in  nickelling  with  a  feeble  current.  The  deposit  itself  is 
dull  and  somewhat  gray,  but  acquires  a  very  fine  polish  and  pure 
white  color  by  slight  treatment  upon  the  polishing  disks.  With  a 
stronger  current  the  bath  is  also  suitable  for  the  direct  nickelling 
of  zinc  articles ;  it  must,  however,  be  kept  strictly  neutral.  The 
bath  works  with  rolled  anodes,  and  requires  but  seldom  a  correction 
of  the  reaction. 

II.  Phosphate  of  nickel,  8}4  ozs. ;  sodium  pyrophosphate,  26^ 
ozs.  ;  water,  10  to  15  quarts.  Dissolve  the  sodium  pyrophosphate 
in  water,  heat  the  solution  to  about  167°  F.  and  add  the  phosphate 
of  nickel  with  constant  stirring.  The  phosphate  of  nickel  is  ob¬ 
tained  as  a  pale  green  powder  by  precipitating  solution  of  nickel 
sulphate  with  sodium  phosphate.  This  bath  yields  a  very  fine  dark 
nickelling  upon  iron,  brass,  copper,  etc.,  as  well  as  directly  without 
previous  coppering  upon  sheet  zinc  and  zinc  castings,  and  may  be 
advantageously  used  for  decorative  purposes  where  darker  tones  of 
nickel  are  demanded. 

III.  A  fairly  good  nickel  bath  for  electro-platers,  having  but  a 
feeble  current  at  their  disposal,  is  obtained  from  a  solution  of  sul¬ 
phate  of  nickel  and  ammonium,  22^  ozs.  ;  sulphate  of  magnesia, 
1 1  ozs.  ;  water,  10  to  12  quarts.  This  bath  precipitates  readily 
and  strongly,  and  a  thick  coating  can  be  deposited  upon  iron  with¬ 
out  fear  of  peeling  off ;  even  zinc  may  be  directly  nickelled  with  a 
comparatively  feeble  current.  The  deposit  is,  however,  rather 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


359 


soft,  with  a  yellowish  tinge,  and  the  bath  does  not  remain  constant 
as  the  anodes  are  but  slightly  attacked. 

New  Nickel  Baths. — I.  The  following  formulae  have  been 
recently  recommended,  but  do  not  offer  any  advantages  over  those 
previously  given. 

I.  Dissolve  25 y2  ozs.  of  neutral  ammonium  tartrate,  35^  ozs. 
of  sulphate  of  nickel,  and  77  grains  of  tannin  in  20  quarts  of 
water. 

II.  Dissolve  17^  ozs.  of  sulphate  of  nickel,  9*^  ozs.  of  tartaric 
acid  and  2 ^  ozs.  of  caustic  potash  in  10  quarts  of  water. 

In  nickelling,  either  cast  or  rolled  plates  of  nickel  are  used  as 
anodes,  some  baths  requiring  cast  anodes  besides  rolled  anodes  in 
various  proportions ;  it  can  here  only  be  indicated  that  the  correct 
proportion  is  that  by  which  the  original  acidity  of  the  bath  is 
maintained  during  the  operation. 

As  regards  the  surface  of  the  anodes  to  be  suspended  in  the  bath, 
it  may  be  laid  down  as  a  rule  that  it  should  be  at  least  equal  in 
size  to  the  surface  of  the  articles  to  be  nickelled ;  in  most  cases  it 
is,  however,  best  that  it  should  be  larger.  For  suspending  the 
anodes  it  is  best  to  use  strong  hooks  of  pure  nickel  wire  ;  with  flat 
articles  the  distance  of  the  anodes  from  them  should  be  from  3^ 
to  4 inches,  and  correspondingly  more  with  objects  in  high 
relief. 

Careful  regulation  of  the  current  is  required  for  the  production 
of  thick  deposits.  The  following  may  be  laid  down  as  a  rule  :  In 
2  or  3  minutes  the  articles  should  show  themselves  plainly  and 
everywhere  coated  with  nickel,  and  no  violent  development  of  gas 
bubbles  should  be  seen.  If  a  deposit  of  nickel  is  not  observed 
after  2  or  3  minutes  the  current  is  too  feeble,  and  if,  on  the  other 
hand,  a  strong  development  of  gas  takes  place,  the  current  is  too 
strong ;  in  the  first  case  the  current  must  be  strengthened  and,  in 
the  latter,  decreased;  as  otherwise  the  articles  are  apt  to  “burn,” 
that  is,  the  metal  will  be  precipitated  as  a  dark-gray  or  black 
deposit  which  discolors  and  renders  it  useless. 

With  a  correctly  regulated  current  it  must  be  possible  to  allow 
the  articles  to  remain  in  the  bath,  without  burning,  for  J^to  2  hours, 


360 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


according  to  the  composition  of  the  bath.  The  sufficient  thickness 
of  the  deposit  is  recognized  by  the  dead-bluish  tinge  the  articles 
assume;  when  in  this  state  they  take  up  but  little  more  nickel  and, 
if  they  are  to  have  a  thicker  deposit,  must  be  scratch-brushed  and 
then  quickly  returned  to  the  bath.  Articles  to  be  coated  with 
a  thick  deposit  must  be  turned  in  the  bath,  that  is,  they  must  after 
some  time  be  so  suspended  that  the  portions  which  first  were  down 
come  up.  Copper,  brass,  bronze,  German  silver,  iron  and  steel 
are  generally  nickelled  directly;  but  zinc,  tin,  lead  and  Britannia 
ware  are  coppered  or  brassed  before  nickelling.  Small  articles 
which  cannot  be  suspended  are  nickelled  in  a  sieve,  it  being  best 
to  heat  the  bath  for  this  purpose.  The  nickelled  articles  are 
thoroughly  rinsed  in  water,  then  immersed  in  hot  water  until  they 
have  acquired  the  temperature  of  the  water,  dried  in  saw-dust  and 
finally  polished. 

Nickelling  of  Knife-blades,  Sharp  Surgical  Instruments,  etc.— 
Most  electro-platers  experience  considerable  trouble  in  nickelling 
sharp-edged  instruments,  the  edges  and  points  being  invariably 
spoiled  either  by  the  deposit  of  nickel  or  in  polishing.  The  fol¬ 
lowing  directions  are  given  for  the  convenient  nickelling  of  such 
instruments  without  any  damage  being  done  to  the  edges. 

New  articles,  which  have  not  been  used,  require  no  special  prepa¬ 
ration.  they  being  at  once  freed  from  grease  and  brought  into  the 
bath.  But  instruments  which  have  been  used  and  are  partly  or 
entirely  coated  with  rust  must  first  be  ground  after  the  removal  of 
the  rust  by  chemical  or  mechanical  means.  The  marks  left  by  the 
stone  or  emery-wheel  are  effaced  by  means  of  the  circular  brush. 
But  in  brushing  the  edges  become  again  dull  if  special  precautionary 
measures  are  not  used.  For  instance,  the  edge  of  a  knife-blade 
must  never  come  in  contact  with  the  brush.  This  is  prevented  by 
firmly  pressing  the  blade  flat  upon  a  soft  support  of  felt  or  cloth, 
so  that  the  edge  sinks  somewhat  into  the  support  without,  however, 
cutting  into  it.  The  edge  is  then  held  downward  and  thus  to¬ 
gether  with  the  support  brought  against  the  revolving  brush.  In 
this  manner  the  blades  can  be  vigorously  brushed  without  fear,  of 
spoiling  the  edges. 


ELECTRO-PLATING,  BRASSING,  COrPERTNG,  ETC. 


361 


The  treatment  in  giving  them  a  high  polish  after  nickelling  is 
the  same.  Freeing  from  grease  may  be  done  in  the  usual  manner 
with  lime-paste,  but  must  also  be  effected  upon  a  soft  support,  the 
same  as  in  polishing.  After  thorough  rinsing  in  clean  water  the 
separate  pieces,  without  being  previously  coppered,  are  brought  di¬ 
rectly  into  the  nickel  bath,  the  composition  of  which  must,  of 
course,  be  suitable  for  nickelling  steel  articles.  The  instruments 
are  first  coated  with  the  use  of  a  strong  current,  the  operation  be¬ 
ing  then  continued  with  a  weak  current,  so  that  the  deposition 
takes  place  slowly  and  with  great  uniformity. 

In  suspending  the  articles  in  the  bath  care  should  be  had  that 
neither  a  point  nor  an  edge  is  turned  towards  the  anodes.  It  is 
best  to  use  a  bath  with  anodes  only  on  one  side,  or  to  interrupt  the 
positive  conduction  on  one  side,  and  to  suspend  the  blades  with 
their  backs  towards  the  anodes.  If,  for  any  reason,  the  instruments 
are  to  be  suspended  between  two  rows  of  anodes,  the  edges  should 
be  uppermost  as  near  as  possible  to  the  level  of  the  bath ;  they 
should  never  hang  deep  or  downwards. 

Phenomena  which  may  Occur  in  Nickelling,  and  the  Means  of 
Avoiding  them. — 1 .  Thearticles  do  not  become  coated  with  nickel  but 
acquire  discolored,  generally  darker,  tones.  Reasojis  :  The  current  is 
either  too  feeble  to  effect  a  separation  of  nickel,  and  the  discolor¬ 
ation  is  due  to  the  chemical  action  of  the  nickel  solution  upon  the 
constituent  metals  of  the  articles.  Remedy :  Increase  the  current 
or  diminish  the  surface  of  suspended  articles;  also  examine 
whether  the  current  actually  passes  into  the  bath,  otherwise  clean 
the  contacts. 

2.  A  deposition  of  nickel  takes  place,  but  it  is  dark  or  spotted 
or  marbled,  even  with  a  sufficiently  strong  current.  Reasons: 
The  bath  is  either  alkaline,  which  has  to  be  ascertained  by  litmus 
paper  and,  if  so,  the  slightly  acid  reaction  of  the  bath  must  be  re¬ 
stored  by  the  addition  of  a  suitable  acid  ;  or,  the  bath  is  too  con¬ 
centrated,  in  which  case  a  separation  of  crystals  will  be  observed ; 
this  is  remedied  by  diluting  with  water;  or,  the  nickel  solution  is 
very  poor  in  metal,  which  can  be  remedied  by  the  addition  of 
nickel  salt ;  it  should  also  be  tested  as  to  the  admixture  of  copper, 


362 


THE  METAL  WORKER’S  nANDY-BOOK. 


since  the  production  of  dark  tones  is  frequently  due  to  this;  in 
this  case  the  bath  is  allowed  to  work  for  some  time,  and  if  the 
content  of  copper  is  inconsiderable  a  white  deposit  will  soon  be 
obtained  ;  or,  the  cleaning  and  dipping  of  the  articles  has  been 
incomplete,  which  is  remedied  by  again  thoroughly  cleaning  them  ; 
or,  the  conducting  power  of  the  bath  is  insufficient,  which  is 
remedied  by  the  addition  of  a  suitable  conducting  salt. 

When  freshly  prepared  baths  yield  dark  nickelling  it  can  gener¬ 
ally  be  remedied  by  working  the  bath  2  or  3  hours. 

3.  A  yellowish  tinge  of  the  nickelling.  Reasons:  Alkalinity 
of  the  bath.  Remedy  :  See  under  2  ;  or,  with  cast-iron,  an  insuf¬ 
ficient  metallic  surface,  which  is  remedied  by  repeating  the  scratch- 
brushing;  or,  unsuitable  composition  of  the  bath. 

4.  The  articles  rapidly  acquire  a  white  deposit  of  nickel, 
but  the  color  soon  changes  to  dull  gray-black,  especially  on  the 
deepest  corners  and  edges.  Reason:  Too  strong  a  current. 
Remedies :  Regulating  the  current,  or  hanging  in  more  articles,  or 
taking  out  elements.  Frequent  turning  of  the  articles. 

5.  The  nickelling  is  white,  but  readily  peels  off  by  scratching 
with  the  finger-nail,  or  by  the  action  of  the  polishing-disk. 
Reasons :  The  current  is  either  too  strong,  which  is  remedied  as 
under  4;  or,  the  bath  is  too  acid.  This  is  remedied  by  the  addi¬ 
tion  of  spirit  of  sal-ammoniac,  potassium  carbonate  or  carbonate 
of  nickel,  according  to  the  composition  of  the  bath  ;  or,  insuf¬ 
ficient  cleaning  and  dipping,  which  is  remedied  by  thorough  clean¬ 
ing  after  removing  the  unsuccessful  deposit  and,  if  it  cannot  be 
entirely  removed,  coppering. 

6.  Though  nickelling  may  proceed  in  a  regular  manner  some 
places  remain  free  from  deposit.  Reasons:  Either  some  of  the 
surfaces  of  the  articles  touch  each  other,  or  air-bubbles  are  in¬ 
closed  in  cavities;  or,  faulty  arrangement  of  the  anodes.  Remedy : 
Removal  of  the  causes. 

7.  The  deposit  appears  with  small  holes.  Reasons:  A  deposit 
of  particles  of  dust  upon  the  articles.  Remedy :  Remove  the  dust 
from  the  surface.  When  there  is  a  general  turbidity  of  the  bath  in 
consequence  of  alkalinity,  add  the  most  suitable  acid  and  boil  and 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


363 


filter  the  bath  ;  or,  insufficient  removal  of  gas-bubbles  from  the 
articles.  Remedy :  Shake  the  negative  poles  by  blows  with  the 
finger. 

8.  Deposition  takes  place  promptly  upon  the  portions  of  the 
articles  next  to  the  anodes,  while  deeper  portions  remain  free  from 
nickel  or  become  black ;  or  the  portions  covered  by  the  suspending 
wire  show  dark  lines.  Reason :  Insufficient  conducting  power  of 
the  bath.  With  large  depressions  this  is  not  remedied  by  the 
addition  of  a  suitable  conducting  salt,  but  requires  treatment  with 
the  hand  anode. 

To  Improve  Defective  Nickelling. — With  the  brass  parts  thoroughly 
cleansed  defective  places  should  not  occur,  but  when  they  happen 
by  accident  or  negligence  recourse  is  had  to  the  so-called  “  doctor.” 
This  consists  of  a  piece  of  nickel  anode  connected  to  the  positive 
pole  by  a  thin  copper  wire.  Around  this  piece  of  nickel,  which 
is  about  the  size  of  a  finger,  a  piece  of  ordinary  muslin  is  wrapped 
several  times.  The  defective  article  is  then  held  on  top  of  the 
positive  pole,  and,  after  dipping  the  piece  of  nickel  in  the  nickel 
solution  until  the  muslin  is  thoroughly  soaked,  it  is  moved  to  and 
fro  over  the  defective  place,  a  nickel  coating  being  thus  formed. 
Defects  in  gilding  or  silvering  may  be  remedied  in  the  same  man¬ 
ner,  a  piece  of  gold  or  silver  and  the  corresponding  solution  being 
of  course  used. 

To  Nickel  Polished  Objects  of  Iron  or  Steel  Without  the  use  of  a 
Battery. — The  method  of  coating  metallic  objects  with  a  thin  layer 
of  nickel  without  the  use  of  a  galvanic  battery  consists  in  placing 
the  article  to  be  nickelled  in  a  solution  of  chloride  of  zinc  and  a 
nickel  salt.  Since,  however,  by  this  method  of  nickelling,  stains 
may  readily  occur  where  the  metal  comes  in  contact  with  the  zinc, 
which  afterwards  would  have  to  be  removed  by  polishing,  a  special 
process  is  employed.  To  a  dilute  5  to  10  per  cent,  solution  of 
chloride  of  zinc  add  enough  nickel  sulphate  to  give  the  solution  a 
deep  green-color,  and  then  heat,  best  in  a  porcelain  vessel,  to  the 
boiling  point.  Then,  without  troubling  about  the  turbidity  of  the 
bath  caused  by  the  separation  of  a  basic  nickel  salt,  immerse  the 
articles,  previously  cleansed  and  freed  from  grease,  in  it  in  such  a 


364 


THE  METAL  WORKER’S  HANDY-BOOK. 


manner  that  they  do  not  touch  each  other,  or  at  least  only  in  a  few 
places,  and  keep  the  whole  boiling  for  30  to  60  minutes,  from  time, 
to  time  replacing  the  water  lost  by  evaporation.  During  the  boiling  a 
bright  layer  of  nickel  is  precipitated  upon  all  portions  of  the 
objects  free  from  grease  or  oxide.  The  boiling  may  without  injury 
be  continued  for  hours,  though  the  thickness  of  the  layer  of  nickel 
will  not  be  essentially  increased  thereby.  The  articles  being 
uniformly  nickelled  are  taken  from  the  bath,  rinsed  off  in  water, 
holding  some  chalk  in  suspension,  and  then  carefully  dried.  The 
layer  of  nickel  thus  produced  will  bear  polishing  with  chalk,  and 
the  process  may  be  recommended  for  articles  requiring  a  thin  but 
firmly  adhering  coating.  The  chloride  of  zinc  used  must  not  con¬ 
tain  any  metal  precipitable  by  iron.  Where  commercial  chloride 
of  zinc  of  a  sufficiently  good  quality  cannot  be  had,  it  is  best  pre¬ 
pared  by  dissolving  zinc  waste  in  pure  hydrochloric  acid  and  allow¬ 
ing  the  solution  to  stand  with  an  excess  of  zinc  for  the  precipitation 
of  metals  precipitable  by  zinc.  After  24  hours  the  solution  is 
filtered  off  and  is  ready  for  use,  whereby  it  has  to  be  taken  into 
consideration  that  it  contains  for  every  part  of  dissolved  metallic 
zinc  nearly  2.1  parts  of  chloride  of  zinc.  The  nickel  sulphate 
used  should  also  be  as  pure  as  possible,  and  the  cold  solution, 
when  brought  in  contact  with  bright  iron,  must  especially  not  de¬ 
posit  any  metal,  for  instance,  copper,  precipitable  by  iron.  Dur¬ 
ing  the  operation,  when  in  consequence  of  the  formation  of  a 
layer  of  nickel,  the  bath  shows  a  pale  green  color,  fresh  nickel  salt 
must  be  added  until  the  intense  green  color  reappears.  The  fluid 
used  for  nickelling  separates,  on  standing  in  the  air,  ferric  hydrate, 
from  which  it  is  freed  by  filtering,  and  it  can  then  be  repeatedly 
re-used  for  nickelling  after  adding  some  solution  of  chloride  of 
zinc  and  nickel  sulphate.  With  the  use  of  cobalt  sulphate  a 
lustrous  layer  of  metallic  cobalt  can  in  the  same  manner  be  pre¬ 
cipitated  upon  polished  objects  of  iron  and  steel. 

To  Imitate  Nickel-plating. — A  sort  of  light  nickel-plating  is 
obtained  by  heating  a  bath  of  pure  granulated  tin,  crude  tartar  and 
water  to  the  boiling  point  and  adding  some  nickel  oxide  heated  to 
a  red-heat.  A  brass  or  copper  object  immersed  in  the  solution 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


365 


becomes  immediately  coated  with  nearly  pure  nickel.  By  adding 
some  carbonate  or  tartrate  of  cobalt  the  fluid  acquires  a  bluish 
coloration,  the  intensity  of  which  depends  on  the  quantity  of 
cobalt  used.  While  this  method  cannot  be  advantageously  used 
for  plating  on  a  large  scale  it  is  serviceable  for  small  work. 

Platinum  Baths. — The  platinum  baths  formerly  proposed  did 
not  yield  quite  satisfactory  results,  the  content  of  platinum  being 
too  small  in  some  of  them,  and  with  others  dense  deposits  could 
not  be  obtained.  A  new  formula  by  Bottger  gives,  however,  quite 
a  good  bath.  A  moderately  dilute  boiling  solution  of  sodium 
citrate  is  added  to  platoso-ammonium  chloride  until  an  excess  of 
the  latter  does  no  longer  dissolve  even  after  continued  boiling. 
The  following  proportions  have  been  found  very  suitable :  Dis¬ 
solve  17^  ozs.  of  citric  acid  in  2  quarts  of  water,  and  neutralize 
with  caustic  soda.  To  the  boiling  solution  add,  with  constant 
stirring,  the  platoso-ammonium  chloride  freshly  precipitated  from 
2.64  ozs.  of  platinum  chloride,  heat  until  solution  is  complete, 
allow  to  cool  and  dilute  with  water  to  5  quarts.  To  decrease  the 
resistance  of  the  bath  to  conductivity  0.7  or  0.8  oz.  of  sal- 
ammoniac  may  be  added  ;  a  larger  addition,  however,  causes  the 
separation  of  dark-colored  platinum. 

The  platoso-ammonium  chloride  is  prepared  by  adding  to  a  con¬ 
centrated  solution  of  platinum  chloride  concentrated  solution  of 
sal-ammoniac  until  a  yellow  precipitate  is  no  longer  formed  on 
adding  a  further  drop  of  sal-ammoniac  solution  to  a  filtered  sample 
of  the  fluid.  The  precipitate  is  filtered  off  and  brought  into  the 
boiling  solution  of  sodium  citrate.  This  bath  works  very  uniformly 
if  the  content  of  platinum  is  from  time  to  time  replenished. 

“The  Bright  Platinum  Plating  Company,”  of  London,  has 
recently  patented  the  following  composition  of  a  platinum  bath  : 
Chloride  of  platinum,  0.98  oz.  ;  sodium  phosphate,  19^  ozs.  ; 
ammonium  phosphate,  3.95  ozs.  ;  sodium  chloride,  0.98  oz.  ;  and 
borax,  0.35  oz.,  are  dissolved  with  the  aid  of  heat  in  6  to  8  quarts 
of  water,  and  the  solution  is  boiled  for  10  hours,  the  water  lost  by 
evaporation  being  constantly  replaced.  The  results  obtained  with 
this  bath  are  not  much  better  than  those  with  Bdttger’s  bath. 


3G6 


THE  METAL  WORKER’S  HANDY -BOOK. 


The  following  bath  has  been  recommended  by  Prof.  Silvanus  P. 
Thompson:  Chloride  of  platinum,  2  parts;  sodium  borate,  16; 
sodium  carbonate,  16;  sal-ammoniac,  2;  water,  150. 

Platinum  baths  must  be  used  hot,  and  even  then  require  a  cur¬ 
rent  of  5  to  6  volts  tension.  An  abundant  development  of  gas 
must  appear  on  the  articles  and  the  anodes ;  the  surface  of  the 
anodes  (platinum  anodes)  must  not  be  too  small,  and  must  be  only 
a  few  centimetres  distance  from  the  articles.  Since  the  platinum 
anodes  do  not  dissolve,  the  content  of  platinum  in  the  bath  be¬ 
comes  constantly  smaller,  and  the  bath  must  from  time  to  time  be 
strengthened.  It  is  then  heated  in  a  porcelain  dish  or  enamelled 
iron  vessel  to  the  boiling-point,  some  fresh  solution  of  sodium 
citrate  is  added,  and  platoso-ammonium  chloride  introduced  as 
long  as  it  dissolves.  A  concentrated  solution  of  platoso-ammonium 
chloride  may  be  kept  on  hand,  and  a  small  quantity  of  it  at  inter¬ 
vals  be  added  to  the  bath. 

To  Platinize  Copper. — Dissolve  platinum  in  aqua  regia,  and  pre¬ 
cipitate  the  solution  with  sal-ammoniac.  Dilute  this  precipitate 
with  much  water,  and  expose  it  in  a  well-luted  receiver  to  a  mod¬ 
erately  strong  heat  for  half  an  hour  until  the  receiver  is  glowing 
hot.  By  this  process  the  precipitate  is  converted  into  a  gray  pow¬ 
der,  which  is  nothing  else  but  very  finely  divided  platinum.  A 
portion  of  this  powder  is  rubbed  with  5  parts  of  mercury  in  a  thor¬ 
oughly  heated  mortar.  From  the  mass  thus  obtained  a  thick 
amalgam  is  formed,  to  which  2  parts  more  of  mercury  are  added 
in  order  to  make  it  more  pliant.  This  platinum  amalgam  when 
applied  to  polished  copper  adheres  very  firmly.  The  operation 
succeeds  still  better  by  mixing  some  chalk  with  the  amalgam. 
Copper  coated  in  this  manner  with  platinum  acquires  by  polishing 
the  lustre  of  silver. 

To  Platinize  by  the  Wet  Method. — The  fluid  required  for  coating 
metals  by  this  method  with  a  layer  of  platinum  is  prepared  by  dis¬ 
solving  1  part  of  chloride  of  platinum  and  1  part  of  pure  honey  in 
8  parts  of  water,  adding  to  the  solution  6  parts  of  spirits  of  wine 
and  2  of  ether,  and  filtering  the  mixture  if  necessary.  After  thor¬ 
oughly  cleansing  and  drying  the  articles,  heat  them  over  a  flame, 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


367 


but  so  that  they  do  not  touch  it,  not  quite  to  a  red  heat,  and  then 
suddenly  immerse  them  in  the  platinizing  solution.  Generally, 
immersing  for  one  minute  suffices,  but  if  necessary  repeat  the  opera¬ 
tion,  the  articles,  before  heating,  being  again  washed  and  dried. 
The  solution  of  platinum  may  be  weaker  or  stronger  than  that  given 
above,  and  of  course  the  appearance  of  the  layer  of  platinum  depos¬ 
ited  upon  the  articles  will  be  accordingly.  It  will  be  readily  seen 
that  this  process  is  only  suitable  for  small  objects,  the  consumption 
of  alcohol  and  ether  making  it  rather  expensive. 

Metals  can  also  be  coated  in  the  wet  way  with  a  layer  of  platinum 
by  cleansing  them  thoroughly  and  then  putting  them  in  a  solution 
of  i  part  of  platoso-ammonium  chloride  in  64  parts  of  water  heated 
to  167°  F.  In  the  course  of  1  to  5  minutes  they  are  taken  out,  and 
the  coating  of  platinum  polished  with  whiting. 

A  moistened  mixture  of  platoso-ammonium  chloride  and  tartar 
may  be  used  for  platinizing  in  the  cold  way,  while  for  platinizing 
by  boiling  a  solution  of  chloride  of  platinum  rendered  slightly 
alkaline  with  carbonate  of  soda  is  used.  The  articles  are  immersed 
into  the  solution,  previously  heated  to  between  131°  and  140°  F., 
and  when  taken  out  rinsed  in  water,  and  rubbed  with  soft,  dry 
leather.  All  the  coatings  obtained  by  the  processes  given  above 
are  very  delicate,  but  they  produce  splendid  effects  upon  orna¬ 
ments  and  statues.  It  is  recommended  to  protect  them  with  a 
varnish  of  wax  dissolved  in  oil  of  turpentine,  or  of  paraffine  dis¬ 
solved  in  benzine. 

To  Coat  Metals  with  Platinum  in  a  Cheap  Way. — Iron  articles 
are  first  coated  with  a  mixture  of  borate  of  lead,  oxide  of  copper, 
and  oil  of  turpentine,  and  then  exposed  to  a  temperature  of  between 
482°  and  626°  F.,  whereby  the  coating  fuses  and  spreads  uniformly 
over  the  iron,  penetrating  its  pores.  If  the  articles  are  to  have  a 
smooth  surface  (enamel-like  appearance)  a  second  coating  consist¬ 
ing  of  borate  of  lead,  oxide  of  lead,  and  oil  of  lavender,  is  in  the 
same  manner  applied  to  the  first.  Upon  both  coatings  a  thin,  uni¬ 
form  layer  of  platinum  can  be  readily  deposited  by  the  application 
by  means  of  a  brush  (or  for  smaller  objects  by  immersion)  of  a 
solution  of  dry  platinic  chloride  in  ether  and  volatile  oils,  and 


368 


THE  METAL  WORKER’S  HANDY-BOOK. 


evaporating  the  fluid  at  a  temperature  not  exceeding  3920  F.  ;  very 
finely  divided  platinum  is  separated,  which  adheres  firmly  to  the 
surface.  If  the  articles  have  been  provided  only  with  the  first- 
mentioned  coating  the  precipitated  platinum  shows  a  dull  color. 
Such  treatment  suffices  for  articles  which  are  simply  to  be  protected 
from  wear  and  tear.  For  the  attainment  of  decorative  effects  it  is, 
however,  recommended  to  provide  the  articles  to  be  platinized  with 
both  the  coatings  mentioned  above.  The  many  uses  to  which  this 
process  can  be  put,  as  well  as  its  cheapness  and  the  great  power  of 
resistance  of  the  coating,  make  it  of  special  value  for  large  indus¬ 
tries. 

Silver  Baths. — These  are  solutions  of  silver  salts  in  potassium 
cyanide,  the  content  of  silver  varying  from  0.35  to  0.88  oz.  of  fine 
silver  per  quart,  according  to  the  desired  thickness  of  the  deposit. 
For  ordinary  galvanic  silvering  0.35  oz.  of  fine  silver  (=  0.56  oz. 
of  nitrate  of  silver,  or  0.47  oz.  of  chloride  of  silver)  is  dissolved  in 
a  solution  of  0.7  oz.  of  98  per  cent,  potassium  cyanide  in  1  quart 
of  water. 

For  heavy  silvering  of  knives,  forks,  etc.,  a  stronger  bath  is  used  : 
0.88  oz.  of  fine  silver  (  =  1.17  oz.  of  chloride  of  silver,  or  1.03  oz. 
of  cyanide  of  silver)  is  dissolved  in  a  solution  of  1.75  oz.  of  98  per 
cent,  potassium  cyanide  in  1  quart  of  water. 

No  accurate  statement  can  actually  be  made  in  regard  to  the  con¬ 
tent  of  potassium  cyanide  in  the  bath,  as  it  depends  on  the  strength 
of  the  current  used.  With  a  very  weak  current,  and  consequently 
slow  precipitation,  somewhat  more  potassium  cyanide  may  be  used 
than  with  a  stronger  current  and  more  rapid  precipitation.  The 
appearance  of  the  anodes,  for  which  sheets  of  fine  silver  are  used, 
moreover,  indicates  whether  the  bath  contains  too  much  or  too 
little  potassium  cyanide.  They  should  become  gray  during  silver¬ 
ing,  and  gradually  reassume  their  white  color  after  the  interruption 
of  the  current.  If  they  remain  white  during  silvering  the  bath 
contains  too  much  potassium  cyanide,  and,  if  they  turn  black  and 
retain  this  color  after  the  interruption  of  the  current,  potassium 
cyanide  is  wanting.  With  a  correct  content  of  potassium  cyanide 
a  beautiful,  fine-grained  deposit  is  obtained,  with  a  strength  of 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


369 


current  of  0.15  to  0.25  amperes  per  15^  square  inches  and  0.5  to 
0.75  volt.  The  deposit  of  silver  is  always  dull. 

It  is  claimed  that  by  the  addition  of  some  bisulphide  of  carbon, 
tar  oil,  etc.,  to  the  silver  bath  a  lustrous  instead  of  a  dull  coating 
is  obtained.  Some  bisulphide  of  carbon  is  added  to  a  small  quan¬ 
tity  of  the  silver  bath,  and  after  thorough  shaking,  some  of  this 
fluid  which  has  absorbed  small  quantities  of  bisulphide  of  carbon 
is  added  to  the  silver  bath. 

It  is  advisable  to  frequently  move  the  articles  to  be  silvered  in 
the  bath,  as  otherwise  streaks  are  apt  to  form  ;  in  large  electro¬ 
plating  establishments  the  articles  are  kept  in  constant  motion  by 
mechanical  devices. 

Before  silvering  the  metals  must  first  be  prepared ;  if  silver  were 
directly  precipitated  upon  copper,  brass  or  German  silver,  the 
coating  would  not  adhere,  and  to  attain  this  the  metals  must  first 
be  amalgamated.  This  is  done  by  dipping  the  articles,  previously 
freed  from  grease,  in  a  dilute  solution  of  mercurous  nitrate  (30  to 
150  grains  per  quart);  they  remain  in  the  solution  only  long 
enough  to  become  uniformly  white.  They  are  then  rinsed  in 
water,  brushed  off  with  a  soft  brush  and  immediately  brought  into 
the  silver  bath.  Iron,  steel,  nickel,  zinc,  tin,  lead  and  Britannia 
ware  must  first  be  coppered  and  then  amalgamated  before  being 
brought  into  the  silver  bath. 

The  articles  remain  in  the  bath  until  they  show  a  dead-white 
coating  (10  to  15  minutes),  when  they  are  taken  out,  brushed  with 
a  not  too  fine  brass  scratch-brush  to  ascertain  that  the  deposit 
adheres,  freed  from  grease,  amalgamated  and  again  brought  into 
the  bath,  where  they  remain  until  the  required  thickness  of  the 
deposit  is  obtained.  Before  taking  the  articles  from  the  bath  they 
are  allowed  to  remain  suspended  for  a  few  seconds,  with  the  current 
shut  off  or  reversed,  which  prevents  the  deposit  from  turning 
yellow. 

If  the  articles  are  to  retain  the  beautiful  white  crystalline  mat 
with  which  they  come  from  the  bath,  they  must,  without  being 
touched  with  the  fingers  or  striking  against  the  sides  of  the  vessel, 
be  thoroughly  rinsed  in  water,  then  dipped  in  clean  hot  water  and 
24 


370 


THE  METAL  WORKER’S  nANDY-BOOK. 


hung  up  free  to  dry.  Immediately  after  drying  they  must  be  pro¬ 
vided  with  a  coating  of  colorless  lacquer,  as  the  silver  quickly 
turns  yellow,  and  besides  is  very  sensitive. 

Forks  and  spoons  of  German  silver  are  frequently  silvered  so 
that  the  deposit  is  thicker  on  the  places  subject  to  the  most  wear. 
This  is  effected  by  laying  the  silvered  articles  between  plates  of 
gutta-percha  of  a  corresponding  shape,  and  held  together  by  rubber 
bands.  In  these  plates  the  places  to  be  further  silvered  are  cut 
out.  By  suspending  the  forks  and  spoons  thus  covered  in  the  bath 
the  unprotected  places  receive  a  further  layer  of  silver,  the  outlines 
of  which  are  later  on  smoothed  down  with  the  burnisher. 

The  silvered  articles  are  finally  scratch-brushed,  they  being 
frequently  moistened  during  this  operation  with  decoction  of  soap- 
root  ;  they  are  then  dried  in  clean,  fine  saw-dust,  and  finally  re¬ 
ceive  a  high  lustre  by  polishing  with  the  steel  or  blood-stone. 

Silvering  by  Contact. — For  silvering  by  contact  with  zinc  the 
following  bath  may  be  used:  98  per  cent,  potassium  cyanide,  8.11 
to  8.81  ozs.  ;  fine  silver  (in  the  form  of  chloride  of  silver  or  nitrate 
of  silver),  3.52  ozs.  ;  distilled  water,  10  quarts.  To  prepare  this 
bath  dissolve  5.64  ozs.  of  chemically  pure  crystallized  nitrate  of 
silver  in  5  quarts  of  distilled  water,  then  dissolve  the  potassium 
cyanide  in  the  remaining  5  quarts  and  mix  both  solutions.  The 
articles  to  be  silvered  must  be  thoroughly  cleansed  by  pickling  and 
amalgamated  by  dipping  into  a  solution  of  0.35  oz.  of  nitrate  of 
mercury  in  1  quart  of  water,  to  which,  gradually  and  with  con¬ 
stant  stirring,  pure  nitric  acid  is  added  until  a  clear  fluid  results. 
In  this  mercury  solution  the  articles  remain  until  they  are  uniformly 
covered  with  a  white  coating.  They  are  then  rinsed  off  in  water 
and,  in  case  the  amalgamation  shows  a  gray  instead  of  a  white  tint, 
brushed.  Before  placing  the  articles  in  the  bath  they  are  wrapped 
round  with  bright  zinc  wire  or  are  brought  in  contact  with  a  bright 
strip  of  zinc  while  in  the  bath,  care  being  had  to  frequently  change 
the  points  of  contact  to  prevent  the  formation  of  stains.  By  the 
contact  of  the  metal  to  be  silvered  with  the  electro-positive  zinc,  a 
weak  current  is  produced  which  effects  the  deposition  of  the  sil¬ 
ver  ;  but  this  taking  place  very  slowly,  it  is  best  to  heat  the  silver 


ELECTRO-PLATJNG,  BRASSING,  COPPERING,  ETC. 


371 


bath.  At  the  same  time  silver  is  precipitated  upon  the  zinc  and 
hence  the  latter  must  be  frequently  freed  from  the  precipitate  and 
brightened  by  means  of  a  file  or  emery-paper. 

Silvering  by  Dipping. — For  silvering  by  this  process  articles  of 
copper,  brass  or  any  other  alloy  of  copper,  as  well  as  coppered  and 
brassed  wares,  the  following  solution  is  recommended :  Crystallized 
nitrate  of  silver,  5.64  drachms;  98  percent,  potassium  cyanide,  1.23 
ozs. ;  water,  1  quart.  To  prepare  the  bath  dissolve  the  silver  salt  in 
1  pint  of  distilled  water,  then  the  potassium  cyanide  in  the  remain¬ 
ing  pint  of  water  and  mix  the  two  solutions.  The  bath  is  heated  in 
a  porcelain  or  enamelled  iron  vessel  to  between  176°  and  1940  F. 
and  the  thoroughly  cleansed  and  pickled  articles  immersed  in  it 
until  they  are  uniformly  silvered  ;  previous  amalgamation  is  not 
necessary.  The  precipitate  is  lustrous  if  the  articles  are  left  but  a 
short  time  in  the  bath,  but  becomes  dull  when  they  remain  longer; 
in  the  first  case  the  deposit  of  silver  is  a  mere  film  and,  while  it  is 
somewhat  thicker  in  the  latter,  it  can  under  no  circumstances  be 
called  solid. 

According  to  Dr.  Ebermayer  the  composition  of  a  silver  bath  for 
dipping  is  as  follows  :  Dissolve  1.12  ozs.  of  nitrate  of  silver  in  water 
and  precipitate  the  solution  with  caustic  potash  ;  then  thoroughly  wash 
the  precipitated  silver  oxide  and  dissolve  it  in  1  quart  of  water, 
which  contains  3.52  ozs.  of  potassium  cyanide  in  solution,  and  finally 
dilute  the  whole  with  1  quart  more  of  water.  For  silvering  the  bath 
is  heated  to  the  boiling  point,  and  the  silver  withdrawn  may  be  re¬ 
placed  by  the  addition  of  moist  silver  oxide  as  long  as  complete 
dissolution  takes  place.  When  the  silvering  is  no  longer  beautiful 
and  of  a  pure  white  color  the  bath  is  useless  and  is  then  evaporated. 

Blanching. — The  process  known  under  this  name  is  used  for 
coating  with  a  thin  film,  or  rather  coloring,  with  silver  small  ar¬ 
ticles,  such  as  hooks  and  eyes,  pins,  etc.  It  differs  from  the  above- 
described  dipping  process,  which  effects  the  silvering  in  a  few 
seconds,  in  that  the  articles  require  to  be  boiled  for  a  longer  time. 
The  process  is  as  follows  :  Prepare  a  paste  from  14. 11  drachms  of 
nitrate  of  silver  precipitated  as  chloride  of  silver,  44  ozs.  of  cream 
of  tartar  and  a  like  quantity  of  common  salt,  by  precipitating  the 


372 


THE  METAL  WORKER’S  HANDY-BOOK. 


solution  of  the  nitrate  of  silver  with  hydrochloric  acid,  washing 
the  chloride  of  silver  and  mixing  it  with  the  above-mentioned 
quantities  of  cream  of  tartar,  common  salt  and  sufficient  water  to 
a  paste,  which  is  kept  in  dark  glass  to  prevent  the  chloride  of  silver 
from  being  decomposed  by  the  light.  Small  articles  of  copper  or 
brass  are  first  freed  from  fat  and  pickled.  Then  heat  in  an  en¬ 
amelled  kettle  3  to  5  quarts  of  rain  water  to  the  boiling  point,  add 
2  or  3  heaping  tablespoon  fills  of  the  above-mentioned  paste  and 
bring  the  metallic  objects  contained  in  a  stone-ware  sieve  into  the 
bath  and  stir  them  diligently  with  a  rod  of  glass  or  wood.  Before 
placing  a  fresh  lot  of  articles  in  the  bath  the  addition  of  silver 
paste  must  be  renewed;  if  finally  the  bath  acquires  a  greenish 
color,  caused  by  the  dissolved  copper,  it  is  no  longer  suitable  for 
the  purpose,  and  is  then  evaporated  and  added  to  the  silver 
residues. 

Cold  Silvering. — In  this  process  an  argentiferous  paste  composed 
as  given  below  is  rubbed  by  means  of  the  finger,  a  piece  of  soft 
leather  or  a  rag  upon  the  cleansed  and  pickled  metallic  surface 
(copper,  brass  or  other  alloys  of  copper)  until  it  is  entirely  sil¬ 
vered.  The  paste  may  also  be  rubbed  in  a  mortar  with  some  water 
to  a  thinly  fluid,  uniform  mass  which  is  applied  with  a  brush  to  the 
surface  to  be  silvered.  By  heating  the  metal,  and  subsequent 
washing,  the  silvering  appears.  The  application  of  the  paste  by 
means  of  a  brush  is  chiefly  made  use  of  for  decorating  with  silver, 
articles  thinly  gilded  by  dipping.  For  articles  not  gilded,  the 
above-mentioned  rubbing  on  of  the  stiff  paste  is  to  be  preferred. 

Composition  of  A?'gentiferous  Pastes. — I.  Silver  in  the  form  of 
freshly  precipitated  chloride  of  silver,*  0.35  oz.  ;  common  salt, 
0.35  oz.  ;  potash,  0.7  oz.  ;  whiting,  0.52  oz.,  and  water,  a  suffi¬ 
cient  quantity  to  form  the  ingredients  into  a  stiff  paste. 

II.  Silver  in  the  form  of  freshly  prepared  chloride  of  silver,* 
0.35  oz.  ;  potassium  cyanide,  1.05  oz.  ;  sufficient  water  to  dissolve 
these  two  ingredients  to  a  clear  solution  and  enough  whiting  to 
form  the  whole  into  a  stiff  paste.  This  paste  is  also  excellent  for 
polishing  tarnished  silver;  it  is,  however,  poisonous. 

*  From  0.56  oz.  of  nitrate  of  silver. 


ELECTRO  PLATING,  BRASSING,  COPPERING,  ETC.  37? 

The  following  composition,  which  is  not  poisonous,  does  excel¬ 
lent  service:  Silver  in  the  form  of  chloride  of  silver,  0.35  oz.  ; 
cream  of  tartar,  0.7  oz. ;  common  salt,  0.7  oz.,  and  sufficient  water 
to  form  the  mixture  of  the  ingredients  into  a  stiff  paste. 

Graining. — In  gilding  parts  of  watches,  gold  is  seldom  directly 
applied  upon  the  copper ;  there  is  generally  a  preliminary  opera¬ 
tion  called  graining  by  which  a  grained  and  slightly  dead  appear¬ 
ance  is  given  to  the  articles.  Marks  of  the  file  are  obliterated  by 
rubbing  upon  a  whet  stone  and  lastly  upon  an  oil  stone.  Any  oil 
or  grease  is  removed  by  boiling  the  parts  for  a  few  minutes  in  a 
solution  of  10  parts  of  caustic  soda  or  potash  in  100  of  water, 
which  should  wet  them  entirely  if  all  the  oil  has  been  removed. 
The  articles  being  threaded  upon  a  brass  wire,  cleanse  them  rapidly 
in  the  compound  acids  for  a  bright  lustre  and  dry  them  carefully  in 
white  wood  saw-dust.  The  pieces  are  fastened  upon  the  even  side 
of  a  block  of  cork  by  brass  pins  with  flat  heads.  The  parts  are 
then  thoroughly  rubbed  over  with  a  brush,  entirely  free  from  grease, 
and  dipped  into  a  paste  of  water  and  very  fine  pumice-stone  pow¬ 
der.  Move  the  brush  in  circles  in  order  not  to  rub  one  side 
more  than  the  other;  thoroughly  rinse  in  clean  water,  and  no  par¬ 
ticle  of  pumice-stone  should  remain  upon  the  pieces  or  the  cork. 
Next  place  the  cork  and  the  pieces  in  a  weak  mercurial  solution, 
composed  of  water,  z\  gallons  ;  nitrate  or  binoxide  of  mercury, 
oz.  ;  sulphuric  acid,  {  oz.,  which  slightly  whitens  the  copper. 
The  pieces  are  passed  quickly  through  the  solution  and  then  rinsed. 
This  operation  gives  strength  to  the  graining,  which,  without  it, 
possesses  no  adherence.  The  following  preparations  may  be  used 
for  graining : 

I.  Silver  in  impalpable  powder,  2  ozs.  ;  finely  pulverized  cream 
of  tartar,  20  ozs.  ;  pulverized  common  salt,  4  lbs. 

II.  Silver  powder,  1  oz.  ;  cream  of  tartar,  4  to  5  ozs.  ;  common 
salt,  13  ozs. 

III.  Silver  powder,  common  salt  and  cream  of  tartar,  equal 
parts  by  weight  of  each.  The  mixture  of  the  three  ingredients 
must  be  thorough  and  effected  at  a  moderate  and  protracted  heat. 
The  graining  is  the  coarser  the  more  common  salt  there  is  in  the 


374 


THE  METAL  WORKER’S  HANDY-BOOK. 


mixture,  and  it  is  the  finer  and  more  condensed  as  the  proportion 
of  cream  of  tartar  is  greater,  but  it  is  then  more  difficult  to  scratch¬ 
brush.  The  silver  powder  is  obtained  as  follows :  Dissolve  in  a 
glass  or  porcelain  vessel  y$  oz.  of  crystallized  nitrate  of  silver  in 
2*4  gallons  of  distilled  water  and  place  5  or  6  bands  of  cleansed 
copper  y  inch  wide  in  the  solution.  These  bands  should  be  long 
enough  to  allow  of  a  portion  being  above  the  liquid.  The  whole 
is  kept  in  a  dark  place  and  from  time  to  time  stirred  with  the  cop¬ 
per  bands.  This  motion  is  sufficient  to  loosen  the  deposited  silver 
and  present  fresh  surfaces  to  the  action  of  the  liquor.  When  no 
more  silver  deposits  on  the  copper  the  operation  is  complete,  and 
there  remains  a  blue  solution  of  nitrate  of  copper.  The  silver 
powder  is  washed  by  decantation,  or  upon  a  filter,  until  there  re¬ 
mains  nothing  of  the  copper  solution.  It  is  then  carefully  dried, 
avoiding  all  pressure  to  prevent  balling. 

Nuremberg  Graining  Powder  is  produced  by  grinding  a  mixture 
of  honey  and  silver-foil  upon  a  ground  plate-glass  with  a  muller 
until  the  proper  fineness  is  obtained.  The  silver  is  separated  by 
dissolving  the  honey  in  boiling  water  and  washing  the  deposited 
metal  in  a  filter  until  no  trace  of  honey  remains.  The  silver  is 
then  carefully  dried  at  a  gentle  heat. 

For  the  purpose  of  graining,  a  thin  paste  is  made  of  one  of  the 
above  powders  and  water  and  spread  by  means  of  a  spatula  upon 
the  watch  parts  held  upon  the  cork.  The  cork  itself  is  placed  upon 
an  earthenware  dish,  to  which  a  rotating  movement  is  imparted  by 
the  left  hand.  An  oval  brush  with  close  bristles,  held  in  the  right 
hand,  rubs  the  watch  parts  in  every  direction  but  always  with  a  ro¬ 
tatory  motion.  A  new  quantity  of  paste  is  added  two  or  three 
times  and  rubbed  in  the  manner  indicated.  The  more  the  brush 
and  cork  are  turned  the  rounder  becomes  the  grain,  which  is  a  good 
quality;  and  the  more  paste  added  the  larger  the  grain.  When 
the  desired  grain  is  obtained  the  pieces  are  washed  and  scratch- 
brushed.  The  brushes  employed  are  of  brass  wires  as  fine  as  hair 
and  very  stiff  and  springy.  It  is  necessary  to  anneal  them  upon  an 
even  fire  to  different  degrees ;  one  soft  or  half  annealed,  for  the 
first  operation  or  uncovering  the  grain  ;  one  harder,  for  bringing 


ELECTEO-PLATING,  BRASSING,  COPPERING,  ETC. 


375 


lip  the  lustre ;  and  one  very  soft  or  fully  annealed,  used  before 
gilding  for  removing  any  marks  which  may  have  been  made  by 
the  preceding  tool  and  for  scratch-brushing  after  the  gilding, 
which,  like  the  graining,  must  be  done  by  giving  a  rotary  motion 
to  the  tool.  If  it  happens  that  the  same  watch  part  is  composed 
of  copper  and  steel,  the  latter  metal  requires  to  be  preserved  against 
the  action  of  the  cleansing  acids  and  of  the  graining  mixture  by  a 
composition  called  resist.  This  consists  in  covering  the  pinions 
and  other  steel  parts  with  a  fatty  composition  which  is  suffi¬ 
ciently  hard  to  resist  the  tearing  action  of  the  bristle  and  wire 
brushes  and  insoluble  in  the  alkalies  of  the  gilding  bath.  A  good 
composition  is :  yellow  wax,  2  parts  by  weight ;  colophony,  3^  ; 
extra  fine  red  sealing-wax,  1  yi  ;  polishing  rouge,  1.  Melt  the 
colophony  and  sealing-wax  in  a  porcelain  dish  upon  a  water  bath 
and  afterwards  add  the  yellow  wax.  When  the  whole  is  thoroughly 
fluid,  gradually  add  the  rouge  and  stir  with  a  wooden  or  glass  rod. 
Withdraw  the  heat,  but  continue  the  stirring  until  the  mixture 
becomes  solid,  otherwise  all  the  rouge  will  fall  to  the  bottom.  The 
flat  parts  to  receive  this  resist  are  slightly  heated  and  then  covered 
with  the  mixture,  which  melts  and  is  easily  spread.  For  covering 
steel  pinions  employ  a  small  gouge  of  copper  or  brass  fixed  to  a 
wooden  handle.  The  metallic  part  of  the  gouge  is  heated  upon  an 
alcohol  lamp,  and  a  small  quantity  of  resist  is  taken  with  it.  The 
composition  soon  melts,  and  by  turning  the  tool  around  the  steel 
pinion  this  becomes  coated.  Use  a  scratch-brush  with  long  wires, 
as  their  flexibility  prevents  the  removal  of  the  composition.  When 
the  resist  is  to  be  removed  after  gilding,  place  the  parts  in  warm  oil 
or  into  tepid  turpentine,  then  into  a  very  hot  soap-water  or  alkaline 
solution,  and,  lastly,  into  fresh  water.  Scratch-brush  and  dry  in 
warm  white  wood  saw-dust.  The  holes  of  the  pinions  are  cleaned 
and  polished  with  small  pieces  of  very  soft  white  wood,  the  friction 
of  which  is  sufficient  to  restore  the  primitive  lustre.  The  gilding 
of  parts  composed  of  copper  and  steel  requires  the  greatest  care, 
as  the  slightest  rust  destroys  their  future  usefulness.  Should  some 
gold  deposit  upon  the  steel  it  should  be  removed  by  rubbing  with 
a  piece  of  wood  and  impalpable  pumice-dust,  tin-putty  or  rouge. 


376 


TIIE  METAL  WORKER’S  nANDY-BOOK. 


After  the  parts  are  grained  in  the  manner  described  the  gilding 
may  be  effected  in  a  gold  bath  composed  according  to  one  of  the 
following  formulae :  I.  Fine  gold  (as  fulminating  gold),  1.97 
drachms;  98  per  cent,  potassium  cyanide,  5.64  to  8.46  drachms, 
according  to  the  strength  of  current  used ;  water,  1  quart.  To 
prepare  this  bath,  dissolve  1.97  drachms  of  fine  gold  in  aquia  regia 
in  a  porcelain  dish  over  a  gas  or  spirit  flame,  and  evaporate  the 
solution  to  dryness.  Continue  the  heating  until  the  solution  is 
thickly  fluid  and  dark  brown,  and  it  congeals  on  cooling  to  a  red- 
brown  laminated  mass.  Too  strong  heating  is  to  be  avoided,  as 
otherwise  the  chloride  of  gold  would  decompose  to  metallic  gold 
and  escaping  chlorine.  Dissolve  the  neutral  chloride  of  gold  thus 
formed  in  1  pint  of  water,  and  add  liquid  ammonia  to  the  solution 
as  long  as  a  yellowish-brown  precipitate  is  formed,  avoiding,  how¬ 
ever,  a  considerable  excess  of  ammonia.  The  precipitate  of  fulmi¬ 
nating  gold  is  filtered  off,  washed,  and  dissolved  in  1  quart  of  water 
containing  8.46  drachms  of  cyanide  of  potassium  in  solution.  Boil 
the  solution,  constantly  replacing  the  water  lost  by  evaporation 
until  the  odor  of  ammonia,  which  is  liberated  by  dissolving  the 
fulminating  gold  in  cyanide  of  potassium,  disappears,  and  then 
filter.  Instead  of  dissolving  the  gold  itself  and  preparing  neutral 
chloride  of  gold  by  evaporation,  it  is  more  convenient  to  use  3.95 
drachms  of  chemically  pure  neutral  chloride  of  gold,  as  furnished 
by  chemical  factories,  and  to  precipitate  the  fulminating  gold  from 
its  solution. 

Too  large  an  excess  of  cyanide  of  potassium  gives  gold  deposits 
of  a  disagreeable  pale  color.  When  working  with  a  strong  current 
the  excess  of  cyanide  of  potassium  need  only  be  small,  while  with 
a  weak  current  it  may  be  greater. 

For  those  who  prefer  to  work  with  gold  baths  prepared  with  yel¬ 
low  prussiate  of  potash  instead  of  potassium  cyanide,  the  following 
formula  is  given:  II.  Yellow  prussiate  of  potash,  8.46  drachms; 
carbonate  of  soda,  8.46  drachms;  fine  gold  (as  chloride  of  gold  or 
fulminating  gold),  30.86  grains;  water,  1  quart.  To  prepare  the 
bath,  heat  the  solutions  of  the  yellow  prussiate  of  potash  and  of  the 
carbonate  of  soda  in  the  water  to  the  boiling-point,  add  the  gold 


ELECTRO-PLATING,  RRASSING,  COPPERING,  ETC. 


377  ’ 


salt,  and  boil  %  hour ;  or  with  the  use  of  freshly  precipitated  ful¬ 
minating  gold,  until  the  odor  of  ammonia  disappears.  After 
cooling,  the  solution  is  mixed  with  a  quantity  of  distilled  water 
corresponding  to  that  lost  by  evaporation,  and  filtered.  This  bath 
gives  a  beautiful  bright  gilding  upon  all  metals,  even  upon  iron  and 
steel.  Suitable  tension  of  current,  3.25  to  3  5  volts. 

Fulminating  gold  when  dried  readily  explodes,  and  hence  should 
not  be  allowed  to  dry,  but  immediately  dissolved  while  in  a  moist 
state. 

The  articles  to  be  gilded  are  suspended  in  the  bath  to  metallic 
holders,  connected  with  the  zinc  pole  of  a  battery,  and  of  a  shape 
appropriate  to  the  nature  and  form  of  the  watch  parts.  One  or 
more  platinum  wires  are  used  for  anodes,  and  are  disposed  in  the 
centre  or  around  the  bath.  The  battery  most  generally  employed  is 
composed  of  three,  four,  five,  or  six  small  Daniel l’s  elements. 
Those  with  balloons,  on  account  of  their  constancy,  should  be  pre¬ 
ferred.  The  slower  the  gold  deposits  the  finer  and  more  adherent 
it  is.  When  the  coating  is  sufficient,  wash  the  articles  in  clear 
water,  and  fix  again  upon  the  cork,  in  order  to  proceed  to  the 
last  scratch-brushing  with  a  decoction  of  licorice  or  of  horse- 
chestnut. 

Birmingham  Silvering. — The  articles  are  first  superficially  silvered 
either  by  the  cold  process  or  by  dipping,  then  immersed  in  a  solu- 
.  tion  of  nitrate  of  silver,  the  concentration  of  which  depends  on  the 
intended  thickness  of  the  coating,  and  finally  heated  by  the  tem¬ 
perature  at  which  the  silver  salt  decomposes,  whereby  metallic 
silver  remains  behind.  By  these  manipulations  the  articles  are 
prepared  for  the  succeeding  operations,  which  consist  in  melting  in 
an  iron  crucible  a  certain  quantity  of  borax,  and  heating  until  the 
silver  melts  in  it.  When  this  temperature  is  attained,  which  is 
recognized  by  dipping  a  small  piece  of  silver  into  the  melted  borax, 
the  silvered  articles  are  introduced  and  rapidly  stirred  about.  The 
operation  is  finished  when  the  borax  runs  freely  from  one  of  the 
articles  taken  from  the  bath,  and  the  article  itself  shows  a  bright 
surface.  Otherwise  the  melting  is  continued,  but  not  to  the  fusing 
point  of  the  metallic  base.  The  articles,  after  being  taken  from 


378 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


the  bath  and  allowed  to  cool  off,  are  boiled  in  dilute  sulphuric  acid 
(i  part  acid  to  12  water)  for  the  removal  of  adhering  particles  of 
borax,  then  rinsed  in  clear  water  and  dried.  They  finally  receive 
a  coating  of  fine  silver  in  the  galvanic  way. 

Mechanical  Silvering  According  to  Bertrand. — The  articles  of 
copper  or  an  alloy  are  first  cleansed,  and  after  coating  them  in  the 
galvanic  way  with  a  thin  layer  of  silver,  covered  with  leaf-silver, 
the  firm  adherence  of  which  to  the  metal  is  then  effected  by  the 
combined  use  of  heat  and  a  steel  brush.  The  temperature  at  which 
the  complete  adherence  of  the  silver  is  effected  is  far  below  that  of 
the  melting-point  of  silver. 

Silvering  of  Iron  According  to  Rinmann. — The  articles  to  be  sil¬ 
vered,  for  instance,  buckles,  spurs,  etc.,  are  first  coated  with  cop¬ 
per  or  brass,  and  the  silvering  executed  upon  the  smoothed  and 
polished  layer  of  copper  or  brass.  Dissolve  0.58  oz.  of  silver  in 
aqua  regia,  and  dilute  the  solution  in  a  porcelain  dish  with  30  or 
40  times  the  quantity  of  water.  Then  pour  in  as  much  solution  of 
common  salt  in  water  as  suffices  for  the  pulverulent  precipitation  of 
the  silver.  Now  pour  the  water  off  from  the  silver,  and  rub  the 
latter  into  a  thin  paste  with  2.2  ozs.  of  sal-ammoniac  and  a  like 
quantity  of  glass-gall  (sandiver).  Cover  with  this  paste  the  brass 
or  copper  layer  of  the  iron  article,  and  spread  it  uniformly  with  a 
stiff  brush.  Both  the  application  of  the  paste  and  brushing  may  be 
repeated  twice  or  three  times.  Dry  each  layer  before  applying  the 
next  by  holding  the  article  over  a  moderate  coal  fire  until  it  no 
longer  smokes.  Then  cool  the  article  in  a  boiled  solution  of  tartar, 
and  brush  carefully  with  a  scratch -brush.  Finally  rinse  it  off  in 
clean  water,  dry,  rub  with  the  polishing-steel  moistened  with  lime 
water,  and  wash  again.  For  dull  silvering  the  operation  is  the 
same,  but  the  article  is  washed  in  warm  water  and  dried. 

To  Silver  Bessemer  Steel  and  Utensils  Manufactured  from  it. — 
The  articles,  etc.,  are  first  carefully  cleansed  with  hot  lye,  then 
slightly  pickled  with  dilute  hydrochloric  acid  and  scoured  with 
fine  sand.  Now  drop  solution  of  mercury  in  nitric  acid  into 
water,  slightly  acidulated  with  hydrochloric  acid,  until  a  clean  strip 
of  copper,  when  dipped  into  the  mixture,  acquires  a  white  coating. 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


379 


But  as  iron,  unlike  other  metals,  does  not  amalgamate  by  mere  dip¬ 
ping,  it  is  immersed  in  the  mercury  solution,  being  at  the  same 
time  in  connection  with  the  zinc  pole  of  a  Bunsen  element,  a  strip 
of  platinum  or  gas  carbon  being  used  as  an  anode  for  the  other 
pole.  The  metal  is  soon  covered  with  a  layer  of  mercury,  and  is 
then  taken  out,  well  washed  and  silvered  in  a  silver  solution.  * 
When  taken  from  the  silver-bath  the  article  is  thoroughly  washed  and 
heated  over  a  coal-fire  in  a  fire-place  with  a  good  draught  until  it 
audibly  hisses  when  touched  with  the  wet  finger.  It  is  then  allowed 
to  cool,  is  thoroughly  brushed  with  the  scratch-brush,  and,  if  neces¬ 
sary,  polished.  To  save  silver  the  ware  may  first  be  covered  with  a 
layer  of  chemically  pure  tin  :  i  part  of  purified  cream  of  tartar  is 
dissolved  in  8  parts  of  boiling  water  and  one  or  more  tin  anodes 
are  connected  to  the  carbon  pole  of  a  Bunsen  element.  The  zinc 
pole  communicates  with  a  well-cleansed  piece  of  copper  and  the 
battery  is  made  to  act  until  enough  tin  has  deposited  on  the  copper, 
when  this  is  taken  out  and  the  iron  ware  put  in  its  place.  The 
ware  when  coated  with  a  layer  of  chemically  pure  tin  is  finally 
silvered.  By  the  use  of  alternately  suspended  strips  of  alpaca  as 
an  anode,  the  deposit  of  silver  can  be  somewhat  alloyed  with  the 
tin.  The  articles  thus  produced  are  considerably  cheaper  than 
silvered  ware  of  brass,  German  silver,  etc. 

Alloy  for  Silvering. — This  alloy  consists  of  tin,  80  parts;  lead, 
18;  silver,  2;  or  tin,  90  parts;  lead,  9;  silver,  1.  Melt  the  tin, 
and  when  the  bath  shows  a  lustrous  white  color  add  the  granulated 
lead  and  stir  the  mixture  with  a  pine  stick ;  then  add  the  silver  and 
stir  again.  Increase  the  fire  for  a  short  time  until  the  surface  of 
the  bath  assumes  a  light  yellow  color,  then  stir  thoroughly  and  cast  the 
alloy  into  bars.  The  operation  of  silvering  is  as  follows :  The  article, 
for  instance  a  knife-blade,  is  dipped  into  diluted  hydrochloric  or 
sulphuric  acid,  rinsed  in  clean  water,. dried,  rubbed  with  a  piece 
of  soft  leather  or  dry  sponge,  and  then  exposed  in  a  muffle  to  a 
temperature  of  158°  to  176°  F.  for  five  minutes.  The  effect  of 
this  treatment  is  to  render  the  surface  of  the  iron  or  steel  porous. 
With  iron  not  very  good  and  coarsely  porous  the  silvering  process 
is  difficult  to  execute.  With  steel,  however,  the  process  is  easy; 


380  TITE  METAL  WORKER’S  HANDY-BOOK. 

the  article  heated  to  about  140°  F.  is  dipped  into  the  alloy  melted 
in  a  crucible  over  a  moderate  fire.  The  bath,  which  must  be  com¬ 
pletely  liquid,  is  stirred  with  a  pine  or  poplar  stick.  The  surface 
should  show  a  fine  silver-white  color.  One  or  two  minutes  dipping 
suffices  for  a  knife-blade.  When  taken  from  the  bath  the  article  is 
dipped  into  cold  water  or,  if  necessary,  hardened  and  tempered  in  the 
usual  manner.  It  is  then  rubbed  dry  and  polished  without  heating. 
Articles  thus  treated  have  the  appearance  of  silver,  and  resist  oxida¬ 
tion  in  the  air.  To  protect  them  from  the  action  of  acid  liquids 
they  are  first  dipped  in  an  amalgam  bath  of  69  parts  mercury,  39 
parts  tin,  and  1  part  silver,  then  while  hot  in  melted  silver,  and 
electro-plated  with  silver.  This  method  of  silvering  is  claimed  to 
be  very  durable  and  not  costly. 

Tin  Baths. — Electro-tinning  is  but  seldom  executed.  A  good 
tin  bath  is  obtained  by  dissolving  0.35  oz.  of  pyrophosphate  of 
soda  and  15.43  grains  of  tin  salt  in  1  quart  of  water.  This  bath 
requires  an  average  current  of  2.5  volts  tension,  cast-zinc  plates 
being  used  as  anodes.  Zinc,  copper  and  brass  objects  are  directly 
tinned  in  this  bath.  Iron  and  steel  articles  are  first  coppered  or 
treated  with  the  following  composition  :  Dissolve  with  the  aid  of 
heat,  in  an  enamelled  cast-iron  vessel,  ammonia  alum  n  ozs.  and 
fused  protochloride  of  tin  yi  oz.  in  4*4  gallons  of  water.  The 
pieces  of  iron  previously  cleansed  and  rinsed  in  cold  water  are  im¬ 
mersed  in  the  solution  as  soon  as  it  boils.  They  are  immediately 
covered  with  a  film  of  tin  of  a  fine,  white,  dead  lustre,  which  may 
be  rendered  bright  by  friction.  The  bath  is  maintained  at  the 
proper  strength  by  small  additions  of  fused  protochloride  of  tin. 

Though  the  tin  bath  given  above  suffices  for  all  cases  an  alkaline 
tin  bath  first  proposed  by  Eisner  may  be  mentioned  ;  its  composition 
is  as  follows  :  Crystallized  tin  salt,  7  ozs.  ;  water,  1  quart ;  and 
sufficient  potash  lye  of  io°  Be.  to  dissolve  the  precipitate  formed. 
The  solution  of  the  tin  salt  in  the  water  is  mixed  with  potash  lye 
of  the  stated  concentration  until  the  precipitate  of  zinc  hydrate 
which  is  formed  is  redissolved  ;  some  electro-platers  recommend 
the  addition  of  0.35  oz.  of  potassium  cyanide  to  the  bath.  With- 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


381 


out  this  addition  the  bath  requires  3.75  to  4  volts,  and,  with 
it,  3-5- 

Tin  baths  must  not  be  used  at  a  temperature  below  68°  F.  ;  they 
require  according  to  their  composition  a  current  of  2  to  3  volts. 
Too  strong  a  current  causes  a  pulverulent  separation  of  the  tin 
which  does  not  adhere  well. 

Tinnitig  by  Contact. — Suitable  solutions  for  tinning  by  contact 
with  zinc  in  the  boiling  tin  bath  are  as  follows : 

I.  Pulverized  tartar,  3.52  ozs.;  alum,  3.52  ozs.  ;  fused  proto¬ 
chloride  of  tin,  14.11  drachms;  rain-water,  10  quarts. 

II.  Potassium  pyrophosphate,  7  ozs.  ;  crystallized  protochloride 
of  tin,  0.7  oz.  ;  fused  protochloride  of  tin,  2.82  ozs.;  water,  10 
quarts. 

III.  For  Tinning  by  Dipping. — Potassium  pyrophosphate,  5.64 
ozs.  ;  fused  protochloride  of  tin,  1.23  oz.  ;  rain-water,  10  quarts. 

Formula  I.  and  II.  yield  good  results.  To  tin  by  contact,  heat 
the  bath  to  boiling  and  suspend  the  clean  and  pickled  articles  in 
contact  with  pieces  of  zinc,  or  better,  wrapped  around  with  zinc- 
wire  spirals,  care  being  had  to  from  time  to  time  move  them  about 
to  prevent  staining.  Large  baths  which  cannot  be  readily  heated 
are  worked  cold,  the  articles  being  covered  with  a  large  zinc  plate ; 
in  the  cold  bath  the  formation  of  the  tin  deposit  requires,  of  course, 
a  longer  time.  By  using  a  galvanic  current  the  deposit  can  be  made 
as  heavy  as  desired.  By  dipping  in  the  bath  prepared  according 
to  formula  III.,  zinc  can  only  be  coated  with  a  very  thin  film  of 
tin,  which,  however,  can  be  made  as  thick  as  desired  by  the  use 
of  a  battery. 

For  thinning  by  contact  in  a  cold  bath,  Zilken  has  patented  the 
following  solution  :  Dissolve  in  xoo  quarts  of  warm  water,  tin  salt, 
7  to  10.5  ozs.  ;  pulverized  alum,  10.5  ozs.  ;  common  salt,  15.87 
ozs.  ;  and  pulverized  tartar,  7  ozs.  The  cold  solution  forms  the 
tin  bath.  The  articles  to  be  tinned  are  to  be  wrapped  round  with 
strips  of  zinc.  Duration  of  the  process,  8  to  10  hours. 

Tinning  by  Boiling  Articles  of  Iron  and  Steel. — Crystallized  am¬ 
monium-alum,  7  ozs.  ;  crystallized  protochloride  of  tin,  2.82 
drachms;  fused  protochloride  of  tin,  2.82  drachms;  rain  water, 


3S2 


THE  METAL  WORKER’S  HANDY-BOOK. 


io  quarts.  Dissolve  the  ammonium-alum  in  the  hot  water,  and 
when  dissolved  add  the  tin  salts.  The  bath  is  to  be  used  boiling- 
hot,  and  kept  at  its  original  strength  by  an  occasional  addition  of 
tin  salt.  The  clean  and  pickled  iron  articles  being  immersed  in 
the  bath  become,  in  a  few  seconds,  coated  with  a  firmly  adhering 
film  of  tin  of  a  dead-white  color,  which  may  be  polished  by 
scratch-brushing  or  scouring  with  saw-dust  in  the  polishing  drum. 
Tinning  by  boiling  in  the  bath,  composed  as  above  given,  is  the 
most  suitable  preparation  for  iron  and  steel  articles  which  are  to  be 
subsequently  strongly  tinned  by  the  galvanic  process.  To  be  en¬ 
tirely  sure  of  success  it  is  recommended  to  thoroughly  scratch¬ 
brush  the  articles  after  boiling,  to  replace  them  in  the  bath,  and 
then  suspend  them  in  a  bath  composed  of  crystallized  sodium 
pyrophosphate,  3.52  ozs. ;  fused  tin  salt,  0.35  oz.  ;  and  water,  10 
quarts.  To  prepare  the  bath  dissolve  the  sodium  pyrophosphate  in 
the  water,  suspend  the  tin  salt  in  a  small  linen  bag  in  the  bath, 
and  move  the  bag  to  and  fro  until  its  entire  contents  are  dissolved. 

Another  Very  Suitable  Bath  is  as  follows:  98  percent,  cyanide 
of  potassium,  3.52  ozs.;  potassium  carbonate,  35.27  ozs. ;  proto¬ 
chloride  of  tin,  14. 11  drachms;  water,  10  quarts. 

To  Tin  Small  Brass  or  Copper  Objects. — Prepare  a  bath  from 
pulverized  tartar,  3.52  ozs.  ;  protochloride  of  tin,  14.11  drachms; 
water,  10  quarts;  and,  after  heating  the  bath  to  boiling,  immerse 
the  objects  to  be  tinned  (pins,  hooks,  handles,  eyes,  etc.)  in  a 
tin  sieve  or  in  contact  with  a  piece  of  zinc  ;  frequent  stirring  with 
a  tin  rod  shortens  the  process. 

Another  Method,  given  by  Bottger,  gives  good  results.  Dissolve 
oxide  of  tin  by  boiling  with  potash  lye,  and  place  the  copper  or 
brass  objects  in  the  boiling  solution  in  contact  with  tin  shavings. 

Eisner' s Bath  yields  equally  good  results.  It  consists  of  a  solu¬ 
tion  of  equal  parts  of  tin  salt  and  common  salt  in  rain  water.  The 
manipulation  is  the  same  as  given  above. 

Stolba's  APethod  of  Tinning. — Prepare  a  solution  of  1.76  oz.  of 
tin  salt  and  5.64  drachms  of  pulverized  tartar  in  1  quart  of  water, 
moisten  with  this  solution  a  small  sponge,  and  dip  the  latter  into 
pulverulent  zinc.  By  then  rubbing  the  thoroughly  cleansed  and 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


383 


pickled  articles  with  the  sponge  they  immediately  become  coated 
with  a  film  of  tin.  To  obtain  uniform  tinning  the  sponge  must  be 
repeatedly  dipped,  now  into  the  tin  solution,  and  now  in  the  zinc 
powder,  and  the  rubbing  continued  for  a  few  minutes. 

Cold  Tinning.- — Block  tin  dissolved  in  hydrochloric  acid  with 
a  little  mercury  forms  a  very  good  amalgam  for  cold  tinning  ;  or, 
i  part  of  tin,  2  of  zinc  and  6  of  mercury.  Mix  tin  and  mercury 
together  until  they  form  a  soft  paste.  Clean  the  metal  to  be 
tinned,  being  careful  to  free  it  from  greasiness.  Then  rub  with  a 
piece  of  cloth  moistened  with  hydrochloric  acid,  and  immediately 
apply  a  little  of  the  amalgam  to  the  surface,  rubbing  it  with  the 
same  rag.  The  amalgam  will  adhere  to  the  surface  and  thoroughly 
tin  it.  Cast-iron,  wrought-iron,  steel  and  copper  may  be  tinned 
in  this  way.  Those  who  find  it  difficult  to  make  soft  solder  adhere 
to  iron  with  sal-ammoniac,  will  find  no  difficulty  if  they  first  tin 
the  surfaces  in  this  manner  and  then  proceed  as  with  ordinary  tin¬ 
plate. 

Tinning  Hard  Steel  or  Case-hardened  Articles. — In  the  first 
place  a  bath  of  melted  tin  will  not  injure  the  temper  or  materially 
soften  hardened  steel  surfaces,  inasmuch  as  tin  melts  at  4420  F.,  and 
polished  steel  acquires  a  straw  color  at  460°  F.  The  iron  or  steel 
articles  must  first  be  freed  from  scale  (if  any),  either  from  the 
foundry  or  forge,  by  means  of  a  pickle  of  dilute  sulphuric  acid,  and 
then  scratch-brushed  or  scoured  with  sand.  If  the  articles  are  of 
steel  and  have  been  quenched  or  hardened  in  oil,  every  trace  of 
the  oil  must  be  removed  by  immersion  in  boiling  soda  lye ;  next 
the  surface  must  be  made  chemically  clean ;  even  the  film  of 
oxide,  due  to  a  pale  straw  color,  will  prevent  the  due  adherence 
of  the  tin  to  the  steel.  Have  a  bath  consisting  of  1  part  of 
hydrochloric  acid  to  about  20  parts  of  water,  hold  the  article 
with  a  pair  of  brazing  tongs  and  stir  it  for  a  few  seconds  in  the 
bath,  withdraw  it,  and,  while  still  wet,  instantly  immerse  it  in  a 
ladleful  of  melted  tin,  the  surface  of  which  should  be  kept  from 
oxidizing  by  a  flush  of  good  clean  tallow.  In  less  than  half  a 
minute  the  article,  when  withdrawn,  will  be  found  completely 


384 


THE  METAL  WORKER’S  HANDY-BOOK. 


tinned.  Of  course  precaution  must  be  taken  not  to  overheat  the 
tin,  but  keep  it  down  to  the  proper  melting  temperature. 

Improved  Process  of  Tinning  Metals. — An  improved  process  for 
coating  metals  with  tin,  by  Borthel  and  Moller,  of  Hamburg,  is 
said  to  possess  the  advantage  of  preventing,  or  at  least  delaying, 
oxidation.  The  process  can  be  employed  with  special  advantage 
for  tinning  cast-iron  cooking  utensils,  household  and  other  im¬ 
plements  of  cast-iron,  as  the  employment  of  poisonous  enamel  is 
avoided  and  a  much  higher  degree  of  polish  attained.  The  pro¬ 
cess  can  also  be  employed  for  protecting  architectural  or  other 
iron  decorations  from  rusting  by  the  coating  of  tin  or  of  another 
metal  without  detriment  to  the  sharpness  of  the  form,  as  is  the 
case  with  the  customary  oil  or  bronze  paints.  In  order  to  produce 
a  perfectly  even  coating  of  tin  on  cast-iron,  the  latter  is  first  pro¬ 
vided  with  a  thin  coating  of  chemically  pure  iron,  regardless  of 
the  form  of  the  casting.  This  coating  is  produced  in  a  galvanic 
manner  in  a  bath  composed  as  follows:  21.16  ozs.  of  sulphate  of 
iron,  Fe  S  O,  are  dissolved  in  5  quarts  of  water,  to  which  is  added 
a  solution  of  about  84.72  ozs.  of  carbonate  of  soda,  Na  C  O,  in  5 
quarts  of  water.  The  resulting  precipitate  of  ferrocarbonate  is  dis¬ 
solved  insmall  quantities  in  concentrated  sulphuric  acid  until  the  fluid 
has  a  green  color.  The  bath  is  then  rendered  aqueous  by  adding 
about  20  quarts  of  water.  Blue  litmus  paper  dipped  in  the  bath  must 
assume  a  deep  claret  color,  and  red  litmus  paper  remain  unchanged. 

The  objects  to  be  provided  with  a  coating  of  chemically  pure  iron 
are  placed  in  the  bath  opposite  to  the  anode  of  cast  or  wrought- 
iron,  and  both  parts  connected  to  the  corresponding  poles  of  a 
dynamo-machine,  electric  battery  or  other  appropriate  source  of 
electricity.  In  a  very  short  time  the  objects  placed  in  the  bath 
are  covered  with  a  coating  of  iron,  the  thickness  of  which  depends 
on  the  duration  of  the  action  of  the  bath  or  the  strength  of  electric 
current.  The  coated  objects  are  then  well  rinsed  in  clean  water, 
dried,  then  painted  with,  or  immersed  in,  a  solution  of  ammonia 
in  chloride  of  zinc,  or  chloride  of  zinc  alone,  and  then  immersed 
in  a  vessel  containing  melted  tin.  The  tin  adheres  with  great 
tenacity  to  the  prepared  surface,  and  the  surplus  of  tin  can  be 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


385 


readily  removed  by  a  brush  or  in  another  manner.  If  the  object 
to  be  tinned  is  of  such  size,  or  so  complicated  in  form  that  it 
cannot  be  readily  immersed  in  molten  tin,  it  can  be  placed  in  a 
galvanic  tin  bath,  which  can  be  readily  made  into  any  desired  size. 
In  this  bath  it  is  provided  with  a  layer  of  tin  of  desired  thickness, 
which,  after  having  been  painted  either  with  a  solution  of  chloride 
of  zinc,  or  of  ammonia  in  chloride  of  zinc,  can  be  heated  to  such 
a  degree  that  the  tin  is  uniformly  melted  on  to  the  object. 

In  like  manner  objects  cast  or  made  of  lead,  or  other  readily 
melting  metals  which  would  lose  their  form  by  melting  when  im¬ 
mersed  in  melted  tin,  are,  previous  to  tinning,  provided  with  a 
coating  of  tin  in  a  galvanic  bath,  as  mentioned  above,  without 
being  subjected  to  heat  for  melting  the  layer  of  tin  deposited  on 
the  same.  With  objects  of  wrought  or  rolled  iron,  or  which  do 
not  require  the  before  described  treatment,  i.  e.,  the  production 
of  a  coating  of  chemically  pure  iron,  it  will  be  sufficient  to  care¬ 
fully  clean  the  same  and  paint  them  with  a  solution  of  ammonia 
in  chloride  of  zinc,  or  a  concentrated  solution  of  chloride  of  zinc. 
This  tinning  process  combines  the  advantage  of  simple  manipula¬ 
tion  and  great  durability  of  the  coating  with  cheapness  of  manu¬ 
facture,  which  is  partially  attained  in  the  saving  of  tin. 

To  Tin  Kettles. — The  kettle  to  be  tinned  is  first  freed  from  oxide, 
etc.  It  is  then  coated  with  a  io  per  cent,  solution  of  chloride  of 
tin,  to  which  as  much  purified  tartar  as  will  lay  upon  the  point  of 
a  knife  has  been  added.  Now  rub  thoroughly  the  moistened 
places  with  coarse  zinc  powder,  obtained  by  pulverizing  zinc  just 
congealed.  This  process  may  be  used  for  brass,  cast  and  wrought- 
iron,  and  also  for  steel.  The  tinning,  to  be  sure,  is  thin,  but  it 
adheres  firmly,  and  a  thicker  coat  can  be  obtained  by  repeating 
the  process  after  a  few  minutes.  Finally  the  kettle  is  rinsed  off 
and  polished  in  the  usual  manner,  for  instance,  with  whiting. 

To  Tin  Lead  Plates. — Heat  the  plates  to  the  melting  point  of 
tin,  next  scatter  powdered  colophony  upon  them,  then  pour 
melted  tin  over  them  and  spread  out  and  rub  on  both  the  colo¬ 
phony  and  tin  with  tow;  finally  wipe  off  the  excess  of  tin.  Lead 
25 


386 


THE  METAL  WORKER’S  HANDY-BOOK. 


plates  tinned  in  this  manner  on  one  or  both  sides  can  be  rolled 
out  as  desired. 

To  Prepare  Tinned  Lead  Pipes. — According  to  Grand’s  method 
for  the  manufacture  of  such  pipes,  a  cylindrical  mould  with  a 
hollow  pivot  is  placed  horizontally  upon  a  lathe  or  other  machine 
which  will  give  it  a  quick,  revolving  motion.  As  much  melted 
lead  as  is  necessary  for  lining  the  interior  surface  with  a  sufficient 
thickness  is  then  introduced  through  the  above-mentioned  hollow 
pivot.  The  machine  is  now  set  in  rapid  motion,  and  the  melted 
metal  is  forced  by  centrifugal  force  against  the  inner  surface  of  the 
mould,  forming  a  hollow  cylinder  of  uniform  thickness.  Through 
the  same  pivot  a  corresponding  quantity  of  melted  tin  is  then 
introduced,  which  by  reason  of  the  constant  revolution  deposits 
itself  firmly  upon  the  inner  surface  of  the  previously  formed  cylin¬ 
der  of  lead.  The  tube  thus  made  can  be  drawn  out  in  the_  usual 
manner. 

To  Make  “Ponte  Argentine,"  or  Tinned  Cast-iron. — Dissolve  in 
250  quarts  of  water  6.6  lbs.  of  sodium  pyrophosphate,  and  add  1.1 
lb.  of  ordinary  and  1.65  lb.  of  dried  and  fused  tin-salt.  Heat  the 
whole  to  176°  F.,  and  place  in  it  the  iron  articles,  together  with  a 
few  pieces  of  tin.  In  working  on  a  large  scale,  the  fluid  and  the 
articles  to  be  tinned  are  brought  into  large  vats  provided  with  an 
axis,  which  can  be  set  in  motion  by  a  suitable  mechanism. 

Zinc  Baths. — The  deposition  of  zinc  in  a  galvanic  way  being 
connected  with  certain  difficulties,  it  is  but  little  applied  in  practice, 
and,  hence,  only  the  compositions  of  a  few  baths,  which  yield  the 
best  results,  are  given. 

I.  Dissolve  2  ozs.  of  caustic  potash  in  x  pint  of  water,  add  to  the 
solution  one  of  0.35  oz.  of  chloride  of  zinc  and  0.7  oz.  of  sal- 
ammoniac  in  1  pint  of  water,  and  stir  until  the  precipitate  at  first 
formed  is  redissolved.  Rolled  sheets  of  zinc  are  used  as  anodes, 
and  a  current  of  a  tension  of  about  3  volts  is  required.  The  articles 
to  be  zinced  must  be  frequently  moved  about,  as  the  zinc  has  a 
tendency  to  deposit  only  upon  the  portion  nearest  to  the  anodes, 
and,  furthermore,  they  must  be  frequently  scratch-brushed  and 
replaced  in  the  bath.  It  is  advisable  to  warm  the  bath. 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


387 


II.  Alum,  3 y2  ozs. ;  zinc  oxyhydrate,  0.35  oz.  ;  water,  1  quart. 
Dissolve  0.8  oz.  of  sulphate  of  zinc  in  1  pint  of  water,  and  carefully 
add  potash  lye  until  a  further  drop  of  it  produces  no  longer  a  pre¬ 
cipitate;  an  excess  of  potash  lye  must  be  avoided,  as  it  dissolves 
the  zinc  oxyhydrate.  The  precipitate  is  filtered  off,  washed  with 
water,  and  the  moist  zinc  oxyhydrate  mixed  with  the  solution  of 
the  alum  in  the  water,  whereby  it  becomes  completely  dissolved. 
This  bath  requires  a  tension  of  current  of  from  3  to  3.5  volts. 

III.  Sulphate  of  zinc,  2^  ozs.  ;  water,  1  quart;  and  potash  lye 
sufficient  to  redissolve  the  precipitated  zinc  oxyhydrate.  This  bath 
also  works  quite  well,  and  requires  from  2.75  to  3  volts,  and  1.5 
amperes  per  15^  square  inches. 

To  Zinc  Copper  and  Brass  Without  a  Battery. — Pour  over  finely 
granulated  zinc  or  zinc-dust  in  a  porcelain  or  other  non-metallic 
vessel  a  concentrated  solution  of  sal-ammoniac  and  heat  to  the 
boiling  point.  Pickle  the  articles  to  be  zincked  with  somewhat 
dilute  hydrochloric  acid  and  throw  them  into  the  boiling  solution. 
By  continued  boiling  the  articles  become  in  a  short  time  coated 
with  a  very  bright  layer  of  zinc.  Finely  granulated  zinc  is  obtained 
by  pouring  the  melted  metal  into  a  strongly  heated  iron  mortar, 
and  thoroughly  and  quickly  rubbing  the  fluid  mass  with  the  iron 
pestle  until  it  congeals. 

Another  Process  is  as  follows:  Commercial  zinc  gray,  i.  <?. ,  very 
finely  divided  metallic  zinc,  is  boiled  several  hours  with  a  concen¬ 
trated  solution  of  caustic  soda.  The  articles  to  be  zincked  are  then 
immersed  in  the  boiling  fluid,  and,  the  boiling  being  continued, 
become  in  a  short  time  coated  with  a  very  bright  layer  of  zinc. 
When  a  copper  article  thus  coated  with  zinc  is  carefully  heated  in 
an  oil  bath  to  between  248°  and  284°  F.,  the  zinc  alloys  with  the 
copper,  formijig  a  sort  of  bronze  similar  in  color  to  tombac. 

To  Zinc  Iron  in  the  Cold  Way. — This  process  may  be  used  to 
protect  iron  from  rust.  A  mixture  of  finely  pulverized  zinc  with 
oil  and  a  siccative  is  applied  with  an  ordinary  brush,  one  applica¬ 
tion  being,  as  a  rule,  sufficient.  Coating  the  article  twice  insures, 
it  is  claimed,  complete  immunity  from  the  effects  of  sea-water  and 


388 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


the  atmosphere.  The  coating  of  zinc  gives  to  the  iron  a  steel-gray 
color,  and  does  not  prevent  the  application  of  other  paint. 

Galvanizing  Sheet-iron. — The  metal  to  be  coated  requires  to  be 
freed  from  oxide  and  impurities  of  every  description  before  it  will 
take  a  proper  coating  of  zinc.  The  preliminary  cleaning,  however, 
does  not  require  to  be  done  with  such  extreme  care  as  in  the  case 
of  galvanoplastic  deposits.  The  first  step  in  the  process  is,  there¬ 
fore,  the  operation  of  pickling,  i.  e.,  the  removal  of  the  black  scale. 
For  this  operation  there  is  usually  provided  a  stout  rectangular 
wooden  tank,  from  5  to  6  feet  high  and  9  to  10  feet  long,  and  wide 
enough  to  accommodate  from  100  to  200  sheets  at  a  time.  This  con¬ 
tains  the  pickling  liquid,  generally  commercial  sulphuric  acid 
diluted  with  from  10  to  12  parts  of  water;  and  into  this  liquid, 
heated  by  steam,  as  many  sheets  are  immersed  (on  edge)  as  the 
tank  will  accommodate.  In  from  1  to  2  hours  the  scaling  of  the 
iron  is  effected,  a  workman  or  two  all  this  time  industriously  wedg¬ 
ing  the  individual  sheets  apart  with  suitably  contrived  tongs  to 
insure  the  penetration  of  the  pickle  to  all  the  sheets.  This  done 
the  sheets  are  withdrawn  from  the  pickle  tank  and  transferred  to 
large,  shallow  washing  vats  of  wood,  in  which  they  are  washed  in  a 
stream  of  fresh  water.  They  are  next  subjected  to  an  inspection 
in  order  that  any  obstinately  adhering  particles  of  scale  or  cinders 
that  the  acid  may  have  failed  to  take  off  may  be  removed.  For 
this  purpose  they  are  passed,  one  by  one,  to  a  bench  or  table  where 
a  workman  armed  with  a  stiff  brush  and  a  triangular-shaped  steel 
scraper  carefully  examines  each  sheet,  and  removes  such  patches  of 
scale  as  may  yet  adhere  in  spots  upon  the  pickled  sheet.  From  his 
hands  they  pass  into  a  second  shallow  tank  filled  with  clean  water 
(which  should  properly  be  renewed  from  time  to  time)  and  in  which 
they  are  allowed  to  remain  for  12  to  24  hours.  The  purpose  of  this 
washing  is  to  remove  all  traces  of  sulphuric  acid  and  basic  sulphate 
of  iron  from  the  pickled  sheet,  the  retention  of  which  would  other¬ 
wise  act  injuriously  upon  the  character  and  the  durability  of  the 
zinc  coating.  In  order  that  the  work  may  go  on  continuously, 
several  of  such  water-tanks  must  be  provided,  so  that  a  lot  of  iron 
shall  always  be  ready  for  the  next  operation.  This  is  termed 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


389 


“  clearing,”  and  consists  in  immersing  the  sheets  from  the  water- 
tanks  for  a  few  minutes  in  commercial  hydrochloric  acid  contained 
in  a  flat  wooden  tank  like  the  water-tanks  above  described.  This 
treatment  removes  every  trace  of  oxide  from  the  sensitive  iron 
skin,  forms  a  thin  layer  of  chloride  upon  it,  and  renders  the  iron 
insensible  to  oxidizing  influences  during  its  subsequent  manipula¬ 
tion.  From  the  clearing  tank  the  sheets  are  arranged  on  edge  in  a 
rack  to  keep  them  from  touching  each  other  (which  rack  is  com¬ 
monly  mounted  on  a  truck)  and  rolled  twenty-five  or  more  at  a  time 
into  a  drying  chamber.  In  about  20  minutes  or  half  an  hour  they 
are  removed  and  are  then  ready  for  dipping.  The  galvanizing  pot 
for  sheet-iron  work  is  a  rectangular  vessel  of  heavy  boiler  plate, 
riveted  in  the  most  substantial  manner,  about  4  feet  deep  and  12 
feet  long  and  15  to  24  inches  wide  and  capable  of  containing  20  to 
30  tons  of  zinc.  Its  bottom  rests  upon  solid  masonry,  the  brick¬ 
work  being  carried  up  about  it  on  all  sides,  providing  a  fire  space 
all  about  the  sides  of  the  pot,  by  which  the  metal  is  kept  in  a 
melted  state,  and  its  temperature  regulated  to  a  nicety  with  the  aid 
of  draft  spaces  opened  or  closed  by  removing  or  inserting  bricks 
provided  for  the  purpose.  The  temperature  of  the  zinc  bath  is  a  mat¬ 
ter  of  vital  importance  to  the  quality  of  the  work  and  of  great 
economical  importance,  and  it  is  here  that  the  skill  and  experience 
of  the  workman  tells  strongly.  For  sheet-iron  work  the  heat  of 
the  bath  is  kept  at  about  iooo0  F. 

The  zinc  being  of  the  right  heat,  a  thin  centre-plate  of  iron  is 
put  in  position,  its  edge  dipping  slightly  beneath  the  surface  of  the 
zinc,  and  dividing  the  bath  longitudinally  into  two  parts.  The 
object  of  this  contrivance  is  to  insure  that  the  sheets  when  dipped 
and  passed  to  the  other  side  of  the  bath  shall  be  completely  im¬ 
mersed  in  the  melted  metal.  This  object  is  also  accomplished  by 
drawing  the  sheets  through  the  bath  by  means  of  a  pair  of  rollers 
submerged  in  the  melted  metal.  They  are  passed  one  by  one  into 
the  metal,  guided  beneath  the  centre-plate,  and,  as  they  emerge  on 
the  other  side,  seized  at  one  end  by  an  iron  gripper  and  drawn 
through  a  layer  of  sand  strewn  on  the  surface  of  the  metal,  the 
object  of  which  is  to  remove  all  the  superfluous  metal.  The 


390 


THE  METAL  WORKER’S  HANDY-BOOK. 


operations  of  dipping  and  drawing  proceed  at  about  the  rate  of  one 
sheet  per  minute.  In  the  setting  of  the  zinc  coating,  which  takes 
place  almost  instantly  after  the  withdrawal  of  the  sheet  from  the 
bath,  the  beautiful  crystallization  of  the  metal  ensues,  which  is  so 
much  admired.  This  appearance  is  known  to  the  trade  as 
spangling,  and  much  attention  is  given  to  the  preliminary  prep¬ 
aration  of  the  iron  just  described,  upon  the  proper  performance 
of  which  the  size  and  beauty  of  the  spangles  are  largely  dependent. 

From  time  to  time,  as  the  sheets  are  dipped,  a  handful  of  sal- 
ammoniac  is  strewn  upon  the  surface  of  the  metal  bath  for  the  pur¬ 
pose  of  clearing  it  of  oxide  and  insuring  a  perfect  contact  of  the 
clean  metals  with  each  other.  Sometimes  the  centre-plate  and  sand 
are  dispensed  with,  and  the  sheets  are  “dipped  bright.”  From 
the  bath  the  sheets  pass  to  the  rolls  to  be  straightened  ;  next  they 
are  bundled,  then  weighed  and  stamped,  and  are  now  ready  for 
shipment  or  use. 

With  cast-iron  and  general  jobbing  work  the  process  is  sub¬ 
stantially  the  same.  Owing  to  its  greater  impurity,  however,  ob¬ 
jects  of  cast-iron  require  a  much  longer  period  of  immersion  in 
the  metal  than  sheet,  which,  as  stated  above,  takes  the  coating  in¬ 
stantly.  Some  time,  too,  is  required  with  large  and  heavy  castings 
before  they  become  heated  to  the  temperature  of  the  zinc  bath, 
which  is  necessary  before  the  amalgamation  will  ensue.  Castings 
require  on  these  accounts  an  immersion  of  from  15  to  30  minutes. 
Where  small  castings  can  be  “  tumbled,”  and  thus  deprived  of  much 
of  their  adhering  scale  and  sand,  it  is  frequently  unnecessary  to  pickle 
them  in  the  manner  here  described.  In  such  cases  they  are  simply 
cleaned  by  a  few  minutes’  immersion  in  hydrochloric  acid  and 
dipped.  On  the  other  hand,  common  rough  and  unfaced  castings 
require  much  time  and  attention  to  scale  and  prepare  them  for  the 
zinc  bath.  Where  the  articles  are  small  enough  a  lot  of  them  is 
placed  in  a  perforated  iron  ladle  with  a  long  handle  and  dipped, 
with  occasional  shaking,  until  they  have  taken  a  proper  coating. 
They  are  then  removed  from  the  ladle  singly  with  tongs,  the  sur¬ 
plus  metal  being  knocked  off  as  they  are  taken  out.  Hoop  iron 
and  wire  are  passed  through  the  zinc  from  a  reel  at  a  uniform 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


391 


speed.  Wire  cloth  is  beaten  as  it  comes  out  to  remove  the  super¬ 
fluous  metal  that  would  otherwise  clog  up  the  meshes. 

A  matter  which  seriously  troubles  the  galvanizer,  and  which 
entails  considerable  pecuniary  loss  on  him,  is  the  formation  of  what 
is  technically  known  as  dross.  This  is  an  alloy  of  zinc  and  iron 
which  is  formed  in  the  zinc  bath,  partly  by  the  solvent  action  of 
the  zinc  on  the  iron  of  the  pot,  but  chiefly  from  the  iron  articles 
dipped  and  from  the  dripping  off  of  the  superfluous  amalgam  as 
they  come  from  the  bath.  This  alloy  carries  from  90  to  95  per 
cent,  of  zinc  and  from  5  to  10  per  cent,  of  iron  and  other  impuri¬ 
ties.  It  has  a  higher  point  of  fusion  and  a  higher  specific  gravity 
than  zinc ;  hence,  as  it  is  formed,  it  gradually  forms  a  mushy, 
more  or  less  granular,  accumulation  in  the  bath.  While  the  work 
is  going  on  the  agitation  of  the  metal  stirs  up  the  accumulated 
dross  and  keeps  it  floating  through  the  liquid  zinc,  and  as  it  greatly 
interferes  with  the  smoothness  of  the  work  it  must  be  removed  from 
time  to  time.  This  operation,  called  “  dressing, ” is  performed  with 
a  large  perforated  iron  ladle,  through  the  openings  of  which  the 
fluid  zinc  runs  off,  while  the  dross  is  retained,  packed  into  moulds, 
so  as  to  form  slabs  of  about  75  lbs.  weight,  and  in  this  form  is 
usually  sold  to  the  smelters  and  refiners,  who  regain  the  zinc  it  con¬ 
tains  either  by  distillation  or  by  special  patented  procedures.  The 
formation  of  this  dross  is  a  serious  item  of  loss,  amounting  in  some 
establishments  to  as  much  as  30  per  cent,  of  the  whole  amount  of 
zinc  used,  though,  on  the  average,  it  will  not  exceed  25  per  cent. 

The  simplest  method  for  treating  this  alloy,  by  which  much  of 
the  zinc  it  carries  may  be  gained,  consists  in  melting  it  in  a  separate 
iron  pot  and  allowing  it  to  cool  slowly  and  without  disturbance. 
The  upper  layers  of  the  metal,  which  may  be  skimmed  off,  will  be 
found  to  consist  of  nearly  pure  zinc.  In  this  manner  a  large  quan¬ 
tity  of  metal  may  be  regained  from  the  dross  and  used  again. 
The  bottoms,  rich  in  iron,  may  be  disposed  of  to  the  refiners. 

To  prevent  the  adhesion  of  the  dross  to  the  bottom  of  the  pot, 
as  well*  as  to  facilitate  its  removal  therefrom,  in  the  manner  above 
described,  it  is  customary  to  introduce  a  small  quantity  of  lead  into 
the  zinc  bath.  This  metal  does  not  alloy  with  zinc  or  iron,  and  by 


392 


THE  METAL  WORKER’S  HANDY-BOOK. 


reason  of  its  greater  density  it  sinks  to  the  bottom  of  the  pot, 
forming  a  liquid  cushion  on  which  the  dross  and  other  impurities 
float.  To  lend  additional  whiteness  to  these  galvanized  wares 
some  operators  introduce  from  time  to  time  a  small  quantity  of  tin. 

The  spent  “pickle  ”  (sulphuric  acid)  is  collected  in  large  vats  and 
disposed  of  to  the  manufacturers  of  sulphate  of  iron  (green  vitriol). 

To  Galvanize  Old  and  New  Parts.- — Galvanized  articles  subject 
to  strong  wear  frequently  become  damaged.  To  put  them  into 
good  condition,  i.  e.,  to  regalvanize  them,  it  is  necessary  to  first 
thoroughly  clean  them.  With  iron  articles  the  process  is  as  fol¬ 
lows  :  Place  the  articles  in  a  pickle  composed  of  5  to  8  drachms 
of  sulphuric  acid  to  1  quart  of  water,  allowing  them  to  remain  until 
the  oxide  is  eaten  off.  Then  dip  them,  but  only  for  a  moment, 
in  strong  nitric  acid,  and  wash  off  quickly  with  much  water.  To 
large  articles  the  pickle  may  be  applied  with  a  brush,  thoroughly 
scrubbing  afterward  with  sand.  This  scrubbing  is  also  necessary 
when  the  coating  of  zinc  still  adheres  to  some  places  or  parts  of 
the  articles,  since  the  zinc  strongly  oxidizes  in  this  pickle.  Articles 
of  brass  or  copper  are  best  cleansed  with  a  pickle  consisting  of  equal 
parts  of  sulphuric  and  nitric  acids  with  a  small  addition  of  com¬ 
mon  salt.  If  the  articles  are  strongly  oxidized  or  greasy  it  is  best 
to  previously  pickle  them  and  remove  the  grease  by  heating.  The 
pickle  for  this  purpose  consists  of  x  part  sulphuric  acid  in  8  to 
10  water.  The  articles  being  thus  thoroughly  cleaned  may  be 
regalvanized  in  various  ways.  Iron  is  best  galvanized  by  dip¬ 
ping  into  a  fluid  zinc  bath.  The  articles  are  first  dipped  in  a 
concentrated  solution  of  sal-ammoniac,  then  quickly  dried  and  fi¬ 
nally  immersed  in  the  melted  zinc.  Articles  of  large  size  must 
not  be  too  quickly  removed  from  the  bath,  as  otherwise  the  zinc 
adheres  more  firmly  to  places  not  yet  sufficiently  heated  than 
to  others.  To  prevent  the  articles  from  cooling  off  too  quickly 
they  must,  after  being  removed  from  the  zinc  bath,  be  placed  in 
hot,  preferably  boiling,  water.  Small  articles  are  brought  into  the 
zinc  bath  in  a  net  of  strong  iron  wire  and  have  to  be  constantly 
shaken  to  insure  all  the  places  and  all  the  articles  being  coated  with 
zinc.  Copper  and  brass  may  also  be  coated  with  zinc  by  chemical 


ELECTRO-PLATING,  BRASSING,  COPPERING,  ETC. 


393 


means,  the  process  being  as  follows  :  The  articles  are  dipped  into 
a  bath  of  chloride  of  zinc  solution  made  boiling  hot  and  to  which 
a  few  pieces  of  granulated  zinc  are  added.  By  remaining  a  few 
minutes  in  contact  with  the  zinc  the  articles  become  coated  with  a 
very  bright,  firmly-adhering  layer.  The  articles  may  also  be 
dipped  in  a  solution  of  zinc  dust  in  concentrated  caustic  lye.  This 
bath  must  also  be  brought  to  the  boiling  point. 

Metallic  Coating  upon  Flowers  and  Insects  by  the  Galvanic  Way. 
— The  process  consists  in  first  dipping  the  articles  into  an  albu¬ 
minous  fluid  in  order  to  prevent  their  metallization.  They  are 
then  immersed  in  a  bath  of  a  20  per  cent,  nitrate  of  silver  solution, 
and  exposed  to  the  action  of  sulphuretted  hydrogen  to  reduce  the 
adhering  nitrate  of  silver.  The  organic  substance  is  now  ready  for 
the  galvanic  deposit ;  by  the  latter  the  smallest  inequalities  of  sur¬ 
face  become  apparent,  and  small  hairs  scarcely  visible  to  the  naked 
eye  can  be  plainly  distinguished. 

To  Coat  Iron  Articles  with  Other  Metals,  According  to  Newton. — • 
According  to  this  process  the  articles  are  not  prepared,  as  is  gener¬ 
ally  customary,  by  treating  them  with  dilute  acid,  but  by  dipping 
in  ordinary  concentrated  hydrochloric  acid  as  found  in  commerce, 
whereby  the  time  required  for  cleaning  the  articles  is  much  short¬ 
ened.  After  sufficient  action  of  the  acid,  a  few  pieces  of  zinc  are 
dropped  into  thebath  between  the  iron  articles;  the  action  of  the  acid 
upon  the  iron  ceases  immediately,  because  it  attacks  and  dissolves 
the  zinc.  About  1  lb.  of  zinc  suffices  for  half  a  ton  or  more  of 
iron  bolts  or  nails.  Articles  not  very  rusty  or  dirty  are  cleaned  in 
a  minute  or  less.  The  articles  when  taken  from  the  acid  are  imme¬ 
diately  immersed,  without  previous  washing  or  drying,  in  the 
melted  metal,  care  being,  however,  had  to  introduce  them  gradually 
to  prevent  the  scattering  of  melted  metal.  The  union  of  the  metal 
with  the  iron  by  this  process  takes  place  with  greater  ease  and  more 
completely  than  when  the  articles  are  previously  dried  and  exposed 
to  the  air.  The  kind  of  metal  to  be  used  for  coating  the  iron  de¬ 
pends  on  the  intended  use  of  the  article.  Two  alloys  rich  in  lead 
are,  however,  proposed,  because  for  certain  purposes,  for  instance, 
for  ships’  sheathing  and  covering  roofs,  lead  protects  better  than 


394 


THE  METAL  WORKER’S  HANDY-BOOK. 


tin.  For  example:  Tin,  15  parts;  lead,  75;  copper,  5;  and  anti¬ 
mony,  5;  or,  tin,  15  parts;  and  lead,  85.  The  antimony  effects 
a  more  complete  union  of  the  tin  and  lead,  and  without  antimony 
the  copper  appears  only  mechanically  mixed  with  the  lead.  This 
alloy  gives  as  white  a  coating  as  tin  alone,  the  bluish  color  of  the 
lead  being  neutralized  by  the  copper  and  antimony. 


XII. 

FLUXES  AND  LUTES. 

Fluxes. — There  are  numerous  substances  which,  being  them¬ 
selves  easily  fused,  are  added  to  more  refractory  materials  to  pro¬ 
mote  their  fusion;  the  following  articles  are  largely  used  for  this 
purpose :  Crude  tartar,  commercial  cream  of  tartar,  borax,  salt¬ 
petre,  sal-ammoniac,  common  salt,  limestone,  glass,  and  fluor¬ 
spar. 

As  most  metals  are  more  disposed  to  oxidize  when  in  a  molten 
state  than  when  solid,  it  is  usual  to  cover  the  surface  of  the  metal  in 
the  crucible  or  melting-pot  with  some  flux,  to  protect  the  metal 
from  the  action  of  the  air.  In  the  cupola  the  slag  from  the  lime 
answers  this  purpose.  With  the  precious  metals  powdered  charcoal 
is  frequently  used,  as  are  also  borax  and  saltpetre.  Brass  founders 
employ  broken  glass  or  powdered  charcoal.  For  the  more  fusible 
metals  resin  and  oils  are  used. 

The  best  flux  for  alloys  of  copper  and  tin  is  resin.  It  should  be 
added  when  the  metals  are  almost  melted.  In  using  this  flux  the 
copper  is  usually  melted  first  and  the  flux  added.  When  it  is  in 
the  mushy  state,  after  the  flux  has  been  put  in,  the  zinc  and  tin  are 
added.  A  good  flux  for  old  brass  is  common  resin  soap.  It  should 
be  added  in  small  lumps,  and  stirred  down  into  the  metal  when  in 
the  molten  state.  In  forming  alloys  of  different  metals,  the  molten 
metals  should  always  be  kept  under  a  covering  of  black  glass  or  pul¬ 
verized  charcoal  to  prevent  oxidation. 

Black  Flux,  as  it  is  commonly  called,  is  composed  of  7  parts  of 


FLUXES  AND  LUTES. 


395 


crude  tartar,  6  of  saltpetre,  2  of  common  bottle  glass,  and  by  some 
a  small  amount  of  calcined  borax  is  added.  These  ingredients  are 
first  finely  powdered  and  mixed,  and  then  gradually  heated  in  an 
iron  pot  or  ladle,  so  as  to  burn  them  together.  Care  should  be 
taken  not  to  overheat  the  mixture,  and  as  soon  as  thoroughly 
melted  and  mixed  together  it  should  be  removed  from  the  fire  and 
allowed  to  cool.  After  it  has  cooled  it  is  finely  pulverized  and 
sifted,  and  is  then  ready  for  use.  It  has  a  great  affinity  for  moist¬ 
ure,  and  should  be  protected  against  it  by  being  placed  in  glass 
bottles,  and  the  bottles  corked  up  until  wanted  for  use.  This  is  the 
most  powerful  flux  that  can  be  made.  It  is  but  little  employed  in 
forming  or  fluxing  alloys,  but  principally  by  assayers  in  assaying 
different  kinds  of  metallic  ores.  In  these  assays  the  quantity  of 
black  flux  used  varies  according  to  the  qualities  of  ores,  but  the 
amount  is  generally  about  equal  proportions  of  ore  and  flux.  The 
ore  is  first  roasted,  and  then  finely  broken  up  and  mixed  with  the 
flux,  and  the  whole  is  then  rapidly  heated  in  a  crucible.  If  the 
flux  does  not  make  the  slag  sufficiently  fluid  to  allow  the  metal  to 
settle,  a  small  amount  of  calcined  borax  is  added,  which  makes  the 
slag  more  liquid,  and  permits  the  metal  to  pass  to  the  bottom  of 
the  crucible.  The  crucible  is  then  removed  from  the  fire,  and  the 
mixture  is  either  poured  from  it  or  allowed  to  cool  in  it.  After  it 
has  cooled  the  slag  is  knocked  off  with  a  hammer,  and  a  bottom  of 
metal  is  obtained.  When  using  this  flux  the  clay  crucible,  without 
either  clay  or  graphite,  is  preferred,  for  the  flux  is  very  hard  on  a 
crucible  that  contains  either  of  these  substances.  Black  flux  is  used 
by  some  foundrymen  in  melting  the  fine  scrap  sweepings  from  the 
floor,  and  dross  and  refuse  from  the  crucible.  By  melting  these  in 
a  crucible  with  black  flux  they  obtain  considerable  amounts  of 
metal  from  them  that  would  otherwise  be  lost.  In  melting  the 
refuse  with  black  flux  the  common  clay  crucible  should  always  be 
used. 

Gray  Flux  is  a  product  of  the  decrepitation  of  3  parts  of  tartar 
and  2  of  saltpetre  and  contains  considerable  less  carbon  than  the 
black  flux. 

White  Flux  is  obtained  by  the  decrepitation  of  1  part  of  crude 


396 


THE  METAL  WORKER’S  HANDY-BOOK. 


tartar  and  i  to  2  parts  of  saltpetre.  It  contains  chiefly  potassium 
carbonate  besides  potassium  nitrate,  next  small  quantities  of  cal¬ 
cium  carbonate  (from  the  content  of  lime  in  the  crude  tartar),  some 
metallic  chlorides  and  sulphates.  On  account  of  its  content  of 
nitrates  it  is  chiefly  used  as  an  oxidizing  flux.  The  mixture  is  the 
more  effective  the  more  complete  the  mixture  of  tartar  and  salt¬ 
petre.  It  has  great  affinity  for  moisture  and  must  be  kept  in  well- 
closed  bottles. 

Quick  Flux  is  a  mixture  given  by  Beaume.  It  consists  of  salt¬ 
petre,  3  parts;  sulphur,  1,  and  saw-dust  (from  resinous  wood),  1. 
It  promotes  the  fusing  of  metals  which  can  be  readily  converted 
into  sulphides  (copper,  silver)  by  converting  them  into  readily 
fusible  sulphides. 

Flux  for  Reducing  Arsenic. — Carbonate  of  soda,  in  crystals,  8. 
parts ;  finely  powdered  charcoal,  1  part.  Heat  gradually  to  a  red  heat. 

Cornish  Reducing  Flux. — Crude  tartar,  10  parts  ;  saltpetre,  4 ; 
borax,  3.  Powder  together. 

Refining  Flux. — Crude  tartar  and  saltpetre,  equal  parts.  Burn 
together. 

Crude  Flux. — Saltpetre,  1  part ;  cream  of  tartar,  2  parts.  Mix 
with  finely  powdered  charcoal ;  keep  dry  in  an  air-tight  vessel  or 
well  cork  the  bottle. 

Fluxes  for  Arsenical  Compounds. — I.  Dry  potassium  carbonate, 
3  parts ;  cyanide  of  potassium,  1  part. 

II.  Dry  carbonate  of  soda  and  potassium  cyanide,  equal  parts. 

Moreau' s  Reducing  Flux. — Powdered  glass,  free  from  lead,  8 
parts,  and  1  part  each  of  calcined  borax  and  charcoal.  Powder 
well  and  mix. 

Salt  Cake. — In  smelting  expensive  articles  the  use  of  salt  cake 
as  a  flux  greatly  improves  the  appearance  of' the  metal  or  alloy  ;  the 
refuse  uniting  with  the  salt  cake  floats  to  the  surface  of  the  crucible 
and  is  skimmed  off. 

Lutes. — These  are  soft  adhesive  substances,  generally  of  an  earthy 
composition,  used  for  closing  vessels  to  make  them  air  and  gas 
tight,  or  for  coating  over  vessels  or  parts  of  vessels,  to  protect  them 
from  the  effects  of  high  temperatures. 


LACQUERS,  PAINTS  AND  VARNISHES. 


397 


Stourbridge  Clay  in  fine  powder,  made  into  a  paste  with  water, 
will  sustain  a  great  heat. 

Windsor  Loam,  a  natural  mixture  of  sand  and  clay. 

Either  of  the  above  may  be  used  for  coating  vessels  or  for  making 
tight  the  hot  joints  of  metallic  vessels.  Mixtures  of  pulverized 
borax  with  either  of  the  above,  or  with  common  clay,  form  fusible 
fluxes,  useful  for  glazing  over  the  surfaces  of  vessels  so  as  to  close 
their  pores. 

I.  Mix  thoroughly  2  parts  good  clay,  8  parts  sharp  washed  sand 
and  1  part  horse  dung;  then  temper  like  mortar. 

II.  Linseed  or  almond  meal  mixed  to  a  paste  with  milk,  lime 
water  or  starch  paste.  This  lute  stands  a  temperature  of  500°  F. 

Fat  Lutes. — I.  Mix  dry  clay  or  pipe-clay  in  powder  with  drying 
•linseed  oil  into  a  thick  paste.  The  part  to  which  this  is  applied 
must  be  clean  and  dry. 

II.  Plaster  of  Paris  mixed  with  water,  milk  or  weak  glue.  Both 
these  lutes  stand  a  dull  red  heat. 

White-lead,  paste  and  paper,  caoutchouc  and  yellow  wax  are 
also  used  as  lutes  for  various  purposes. 


XIII. 

LACQUERS,  PAINTS  AND  VARNISHES. 

Japanning  Tin. — The  first  process  with  the  tea-tray,  which  is 
made  of  sheet-iron,  is  to  scour  it  well  with  a  piece  of  sandstone, 
which  process  removes  all  the  scales  of  iron,  and  makes  the  surface 
perfectly  smooth.  It  is  then  given  a  coat  of  vegetable  black,  which 
must  be  mixed  with  black  tar  varnish,  and  thinned  with  tar  spirits 
and  well  strained  ;  only  a  small  quantity  of  varnish  is  necessary,  as 
this  coat  may  dry  dead.  The  article  is  then  put  into  a  stove  to 
harden.  The  stove  is  nothing  more  nor  less  than  a  large  oven  ; 
large  of  course  where  a  great  quantity  of  work  is  put  in  at  one  time. 
The  heat  must  be  as  even  as  possible  all  over  the  heated  space,  and 
must  be  free  from  dust.  The  temperature  must  not  be  much,  if 


398 


THE  METAL  WORKER’S  HANDY-BOOK. 


any,  under  21 2°  F. ,  the  articles  to  remain  in  this  temperature  10  to 
12  hours.  When  taken  out  of  the  stove  they  are  allowed  to  get  cold. 
They  then  receive  a  coat  of  black  tar  varnish,  which  must  not  be 
thinned,  except  it  be  so  thick  as  to  be  quite  unworkable,  and  in 
that  case  tar  spirits  should  be  used  sparingly.  A  stiffish  bristle 
brush  with  short  bristles  should  be  employed.  The  varnish  is  dis¬ 
tributed  evenly  all  over  the  surface,  and  must  be  put  on  so  sparingly 
that  it  cannot  “run,”  as  japanners  say,  which  it  is  sure  to  do 
immediately  it  gets  warm,  particularly  on  upright  articles,  if  too 
much  is  put  on.  Two  coats  of  this  varnish  on  the  top  of  the 
vegetable  black  are  frequently  sufficient  when  done  by  an  expert 
hand,  but  a  third  coat  improves  the  work,  and  often  is  indis¬ 
pensable  ;  10  to  12  hours’  hardening  is  requisite  between  the  coats. 
It  is  likewise  necessary  to  rub  down  the  small  lumps  which  will 
appear  after  each  coat,  with  a  piece  of  pumice,  first  made  flat  by 
rubbing  it  on  a  slab  of  slate.  Keep  dipping  the  pumice  in  water. 
This  rubbing  down  must  be  executed  very  lightly,  or  the  smooth 
parts  will  be  scratched.  If  the  article  is  to  be  decorated  with  bur¬ 
nished  gold,  the  first  process  after  coming  out  of  the  stove  the  last 
time  is  to  “  rough  ”  it.  This  is  done  with  very  fine  pumice  sand 
applied  with  some  kind  of  corded  or  roughish  material,  jean  being 
the  material  most  used.  The  process  is  very  laborious,  as  it  requires 
all  the  pressure  that  can  be  employed,  and  that,  too,  for  some  con¬ 
siderable  time.  It  is  part  of  the  polishing.  When  the  surface  has 
been  made  level  by  this,  the  next  thing  is  to  go  through  the  same 
again  ;  but  this  time,  instead  of  using  sand  and  the  cutting  mate¬ 
rial,  black  or  soft  rotten-stone  must  be  employed,  with  flannel  or 
cloth  kept  well  wetted.  This  makes  the  surface  exceedingly 
smooth,  and  ready  to  be  brightened  up  into  a  fine  polish  by  rubbing 
the  sand  up  and  down.  The  workman  so  employed  has  to  keep 
rubbing  the  dry  hand  into  powdered  white  rotten-stone,  also  oc¬ 
casionally  moistening  the  hand  by  placing  it  on  a  wet  cloth  for 
the  purpose.  The  polish  soon  comes  up  under  a  practical  hand. 
It  takes  months  of  practice  in  this  polishing  before  the  hand  obeys 
the  intellect.  The  work  now  passes  to  the  ornamenter.  After  he 
has  put  on  his  ornaments  of  gold  and  color,  it  is  placed  in  a  stove 


LACQUERS,  PAINTS  AND  VARNISHES. 


399 


at  only  a  few  degrees  of  heat,  as  much  heat  would  destroy  his  work. 
When  dry,  that  part  only  of  the  article  which  is  covered  with  orna¬ 
ment  receives  a  coat  of  copal  polishing  varnish.  This  varnish 
does  not  improve  the  appearance,  but  is  necessary  to  preserve  the 
decoration.  No  polish  or  varnish  can  equal  black  varnish,  which 
is  about  a  fourth  the  price  of  copal.  This  varnish  is  put  on  with  a 
flat  camel-hair  brush,  and  will  harden  in  a  heat  of  about  ioo°  F.  in 
4  hours.  If  put  in  too  great  a  heat  it  will  turn  color  and  com¬ 
pletely  spoil  the  work.  It  is  now  ready  for  “finish”  polishing, 
which  consists  of  the  rotten-stone  process  again  and  handing  up  as 
before,  and  last  of  all,  a  few  drops  of  oil  are  used  with  a  sprinkling 
of  water,  and  this  is  called  oiling  off.  It  requires  great  dexterity, 
or,  instead  of  adding  to  the  lustre  with  the  oil,  it  will  completely 
dull  the  surface.  There  are  plenty  of  goods  that  do  not  go  through 
all  these  processes,  and  yet  look  fairly  well ;  such,  for  instance,  as 
grocers’  canisters,  and  numerous  other  articles.  These,  as  soon  as 
they  have  received  the  second  coat  of  black  varnish,  are  taken 
directly  to  the  ornamenter  without  being  “roughed  ”  or  polished, 
and  if  the  varnish  has  been  put  on  well  and  kept  free  from  dust, 
they  look  very  well.  When  no  polishing  is  done  either  before  or 
after  the  ornamenting,  the  article  is  frequently  covered  all  over 
with  the  copal  varnish  coat.  The  only  safe  way  of  obtaining  the 
proper  varnishes  is  to  get  them  from  those  who  supply  japanners. 

When  tin  goods  are  to  be  japanned  the  only  preparation  neces¬ 
sary  is  to  clean  off  all  grease  spots  with  a  piece  of  clean  rag  dipped 
in  turpentine;  and  as  to  heat,  when  it  is  not  too  hot  to  disturb  the 
solder,  it  will  not  hurt  the  black  varnish,  providing  it  is  put  on 
sparingly.  If  not  the  varnish  will  shrivel.  The  finish  upon 
grocers’  canisters  may  be  readily  obtained,  as  there  is  nothing  on 
them  but  good  stoving  and  varnishing — no  polishing.  Colored 
surfaces  are  ground  in  turpentine  in  a  mill,  or  on  a  stone  slab,  and 
mixed  with  mixing  varnish.  If  an  etnerald green  ground  is  required, 
some  let  the  first  coat  be  of  white-lead  mixed  with  varnish,  and 
this  is  followed  by  two  coats  of  the  emerald  green  without  any 
white  in  it.  The  coat  of  white  gives  to  the  green  a  solidity  which 
could  not  be  obtained  otherwise.  A  moderate  heat  is  required  as 


400 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


these  varnishes  will  not  become  hard  without  heat,  but  in  no  com¬ 
parison  to  the  heat  nor  the  time  required  for  black  varnish. 

A  Vermilion  Ground  is  sometimes  first  coated  with  orange-red, 
and  one  coat  of  vermilion  on  that  should  be  sufficient.  When 
the  last  coat  is  dry  or  hard  the  whole  surface  should  be  well  rubbed 
down  with  fine  pumice  sand,  which  can  be  purchased  from  oil  and 
paint  shops ;  but  it  must  be  fine,  and,  if  necessary,  dusted  through 
fine  muslin.  What  is  called  a  “bob”  must  be  made  of  a  piece 
of  jean,  large  enough  to  hold  in  the  hand  conveniently,  and  this 
must  be  dipped  into  water  and  then  into  the  sand ;  this  rubbed 
vigorously  up  and  down  the  work  will  make  it  quite  smooth.  Use 
freely  of  the  water,  but  moderately  of  the  sand.  Afterwards  wipe 
off  all  cleanly  with  a  wash-bather,  and  the  surface  will  be  found  to 
be  dull,  but  smooth.  Exactly  this  method  is  also  used  for  black 
varnished  surfaces.  The  work  is  now  ready  for  ornamenting,  if 
any  ornamenting  is  to  be  done;  if  not,  it  is  ready  for  varnishing 
with  the  clear  varnish,  which  will  at  once  brighten  the  surf.,  e 
which  had  to  be  dulled  in  the  operation  of  smoothing  it. 

Black  Grounds  for  Japanning. — I.  Asphalt,  i  lb.  ;  copaiba  bal¬ 
sam,  i  lb.,  and  a  sufficient  quantity  of  oil  of  turpentine.  The 
asphalt  is  melted  over  a  fire,  and  the  balsam,  previously  heated,  is 
mixed  in  with  it.  The  mixture  is  then  removed  from  the  fire  and 
mixed  with  the  turpentine. 

II.  Moisten  good  lampblack  with  oil  of  turpentine  and  grind  it 
very  fine  with  a  muller  on  a  stone  plate,  then  add  a  sufficient 
quantity  of  ordinary  copal  varnish  and  rub  well  together. 

III.  Asphalt,  3  ozs.  ;  boiled  linseed  oil,  4  quarts;  burnt  umber, 
8  ozs.  ;  and  a  sufficient  quantify  of  oil  of  turpentine.  Melt  the 
asphaltum,  stir  in  the  oil,  previously  heated,  then  the  umber,  and, 
when  cooling,  thin  down  with  the  oil  of  turpentine. 

IV.  An  extra  fine  black  is  prepared  from  amber,  12  ozs.  ;  puri¬ 
fied  asphalt,  2  ozs.  ;  boiled  linseed  oil,  y2  pint;  resin,  2  ozs.  ;  oil 
of  turpentine,  16  ozs.  Fuse  the  gum,  resin  and  asphalt,  add  the 
hot  oil,  stir  well  together,  and,  when  cooling,  add  the  turpen¬ 
tine. 

Black  Japan  for  Tin  Lanterns. — Asphalt,  1  ozs.;  boiled  lin- 


LACQUERS,  PAINTS  AND  VARNISHES. 


401 


seed  oil,  4  pints;  burnt  umber,  4  ozs.  Heat  till  well  mixed,  and, 
when  cool,  add  turpentine  till  of  a  proper  consistence. 

Asphalt  Lacquer  on  Iron. — In  order  to  obtain  the  filed  places 
equally  dark  with  the  rest,  rub  the  iron  lightly  and  thinly  with  the 
best  quality  of  soot  or  bone-black,  then  burn  in  and  rub  off  with 
turpentine.  By  now  coating  the  article  with  asphalt  lacquer  it 
shows  a  uniformly  black  and  durable  color. 

To  Lacquer  Brass. — In  preparing  brass  for  colorless,  or  nearly 
colorless  lacquer,  the  articles,  after  being  annealed,  pickled, 
scoured  and  washed,  are  either  dipped  for  an  instant  into  pure 
commercial  nitric  acid,  washed  in  clear  water  and  dried  in  saw. 
dust,  or  immersed  in  a  mixture  of  1  part  of  nitric  acid  with  4  of 
water  until  a  white  curd  covers  the  surface,  at  which  moment  the 
articles  are  withdrawn,  washed  in  clear  water  and  dried  in  sawdust. 
In  the  first  case  the  brass  will  be  bright ;  in  the  latter  a  dead  flat, 
which  is  usually  relieved  by  burnishing  the  prominent  parts.  Then 
the  articles  are  dipped  for  an  instant  in  commercial  nitric  acid, 
well  washed  in  water  containing  tartar  to  preserve  the  color  till 
lacquered,  and  dried  in  warm  sawdust.  So  prepared,  the  articles 
are  heated  on  a  plate  and  varnished.  Spirit  varnish  is  used,  which 
consists  in  its  simple  form  of  x  oz.  of  shellac  dissolved  in  1  pint  of 
alcohol.  For  imparting  richness  of  color  to  this  simple  varnish 
such  coloring  substances  as  red  sanders,  dragon’s  blood  and  annotto 
are  added.  To  lower  the  tone  of  color  turmeric,  gamboge,  saffron, 
cape  aloes  and  sandarac  are  used.  The  first  group  reddens,  the 
second  yellows  the  varnish,  while  a  mixture  of  the  two  gives  a 
pleasing  orange,  and  various  tints  can  be  got  by  suitable  mixtures. 

Small  circular  work,  after  being  well  scoured  and  burnished,  if 
necessary,  is  best  lacquered  in  the  lathe.  The  work  should  be 
slightly  warmed  over  a  clear  charcoal  fire,  or  in  a  stove,  and  the 
lacquer  applied  very  thinly  with  a  soft  camel’s-hair  brush.  A  char¬ 
coal  brazier  should  be  held  under  the  work  for  a  few  seconds  after 
the  application  of  the  lacquer  to  prevent  chilling.  To  lacquer  a 
flat  surface,  clean  carefully  by  boiling  in  potash  and  water.  Dip 
in  hydrochloric  acid,  if  it  be  desirable  to  heighten  the  color  of  the 
brass ;  wash  well,  first  in  cold  water,  then  in  hot  (removing  any 
26 


402 


THE  METAL  WORKER’S  II ANDY-BOOK. 


black  muddiness  with  a  brush),  and  dry  in  hot  sawdust.  When 
dry,  burnish  if  required.  Place  upon  a  flat  iron  plate,  just  luke¬ 
warm.  Pass  the  lacquer  quickly  but  evenly  over  the  surface  by 
means  of  a  rather  large  but  fine  camel’s-hair  brush.  Be  careful  not 
to  pass  twice  over  the  same  spot,  or  a  ridge  is  almost  sure  to  appear. 
Warm  the  lower  plate  until  the  work  is  quite  dry. 

Lacquer  for  Brass. — Seed  lac,  12  ozs. ;  copal,  4  ozs. ;  dragon’s 
blood,  80  grains;  extract  of  red  sanders  wood,  50  grains;  saffron, 
70  grains;  pulverized  glass,  ^  lb.  ;  spirits  of  wine,  2  quarts. 

Pale  Lacquer  for  Brass. — Methylated  spirits  of  wine,  1  gallon  ; 
shellac,  5  ozs.  ;  sandarac,  4  ozs.  ;  gum  elemi,  1  oz.  Mix  in  a  tin 
flask,  and  expose  to  a  gentle  heat  for  a  day  or  two ;  then  strain  off, 
and  add  gallon  of  spirit  to  the  sediment  and  treat  as  before. 

Pale  Gold  Lacquer  for  Brass. — Methylated  spirits  of  wine,  2 
gallons ;  seed  lac  bruised,  20  ozs. ;  and  red  sanders,  1  oz.  Dissolve 
and  strain. 

Gold  Colored  Lacquer  for  Brass  Watch-cases ,  etc. — Seed  lac,  6 
ozs.  ;  amber  and  gamboge,  each  2  ozs. ;  extract  of'  red  sanders 
wood  in  water,  24  grains ;  dragon’s  blood,  60  grains ;  Oriental  saf¬ 
fron,  36  grains ;  powdered  glass,  4  ozs.  ;  pure  alcohol,  36  ozs.  The 
seed  lac,  gamboge  and  dragon’s  blood  are  pounded  very  fine  on 
porphyry,  or  clean  marble,  and  mixed  with  the  powdered  glass. 
Over  this  mixture  is  poured  the  tincture  formed  by  infusing  the  saffron 
and  the  sanders  wood  extract  in  the  alcohol  for  24  hours,  then  strain¬ 
ing.  Metallic  articles  that  are  to  be  coated  with  this  varnish  are 
heated,  and,  if  they  admit  of  it,  immersed  made  up  in  packets. 

Gold  Lacquer  for  Metallic  Articles. — Prepare  a  concentrated 
solution  of  picric  acid  in  alcohol,  and  add  to  it  alcoholic  solution 
of  pale  shellac  until  a  test  shows  the  desired  gold  color.  Then  add 
for  every  2  lbs.  of  lacquer  2 y2  drachms  of.  boric  acid,  previously 
dissolved  in  as  little  spirit  of  wine  as  possible. 

Gold  Lacquer  for  Tin  Plate. — Carefully  cleanse  the  tin  plate,  and 
apply  with  a  broad  soft  brush  a  coat  of  a  mixture  of  1  part  of  lin¬ 
seed  oil  and  2  parts  of  dark  copal  lacquer.  Dry  the  coated  plates 
in  a  drying  stove.  Tin  plate  thus  lacquered  can  be  bent  and  ham¬ 
mered  without  the  lacquer  cracking  off  or  losing  its  lustre. 


LACQUERS,  PAINTS  AND  VARNISHES. 


403 


Greeti  Lacquer. — Mix  io  ozs.  of  shellac,  12  ozs.  of  turmeric,  8 
ozs.  of  gum  sandarac,  and  2  ozs.  each  of  gum  elemi  and  gamboge 
in  2  gallons  of  methylated  spirits ;  expose  to  a  gentle  heat,  strain, 
add  1  gallon  of  spirit  to  the  sediment,  and  treat  as  before. 

Iron  Lacquer  for  Blacksmiths,  Locksmiths  and  Founders. — A 
lacquer  protecting  the  iron  from  rust  and  presenting  a  beautiful 
black  appearance  is  prepared  as  follows :  Dissolve  8  ozs.  of  asphalt 
in  4  lbs.  of  pine  oil  by  heating  in  a  copper  kettle,  and  add  8  ozs. 
of  colophony.  Solution  must  be  effected  carefully  to  prevent  the 
flame  from  coming  in  contact  with  and  igniting  the  pine  oil  vapors. 
For  coating  iron  on  a  large  scale  asphalt  tar  is  used,  the  links  of 
chains  being  first  freed  from  scales  by  immersion  in  strongly 
diluted  hydrochloric  acid. 

Lacquers  for  Gold. — Alcohol,  1  gallon;  turmeric  lb.;  mace¬ 
rate  for  a  week,  then  filter,  and  add  gamboge,  2  ozs.  ;  shellac,  6 
ozs.  ;  gum  sandarac,  1^  lbs.  ;  dissolve  in  a  warm  bath,  and  add  1 
quart  common  turpentine  varnish.  For  red  lacquer,  use  1  y2  lbs. 
of  annotto  instead  of  the  turmeric,  and  8  ozs.  of  dragon’s  blood 
instead  of  the  gamboge. 

Pale  Lacquer  for  Gold. — Alcohol,  36  ozs. ;  turmeric,  12  drachms; 
dragon’s  blood,  4  drachms;  red  sanders,  1  drachm;  hay  saffron,  2 
drachms;  shellac,  3  ozs.  ;  gum  sandarac,  6  drachms;  gum  mastic, 
6  drachms;  Canada  balsam,  6  drachms;  dissolve,  and  add  4^ 
drachms  of  spirit  of  turpentine. 

Lacquer  for  Philosophical  Instruments. — Gamboge,  3  ozs.  ;  san¬ 
darac  and  elemi,  each  8  ozs.  ;  best  dragon’s  blood,  4  ozs.  ;  terra 
merit  a*  3  ozs.  ;  oriental  saffron,  8  grains ;  seed  lac,  4  ozs.  ;  pul¬ 
verized  glass,  12  ozs.  ;  pure  alcohol,  80  ozs.  The  dragon’s  blood, 
elemi,  seed  lac,  and  gamboge  are  all  pounded  and  mixed  with  the 
glass.  Over  them  is  poured  the  tincture  obtained  by  infusing  the 
saffron  and  terra  merita  in  the  alcohol  for  24  hours.  This  tincture, 

*  Terra  merita  is  the  root  of  an  Indian  plant ;  it  is  of  a  red  color,  and  much 
used  in  dyeing.  In  varnishing  it  is  only  employed  in  the  form  of  a  tincture,  and 
is  particularly  well  adapted  for  the  mixture  of  those  coloring  parts  which  con¬ 
tribute  the  most  towards  giving  metals  the  color  of  gold.  In  choosing  it  be 
careful  to  observe  that  it  is  sound  and  compact. 


404 


TIIE  METAL  WORKER’S  IIANDY-BOOK. 


before  being  poured  over  the  dragon’s  blood,  etc.,  should  be 
strained  through  a  piece  of  clean  linen  cloth,  and  strongly  squeezed. 
If  the  dragon’s  blood  gives  too  high  a  color,  the  quantity  may  be 
lessened  according  to  circumstances.  The  same  is  the  case  with 
tire  other  coloring  matters.  This  lacquer  has  a  very  good  effect 
when  applied  to  many  cast  or  moulded  articles  used  in  ornamenting 
furniture. 

Lacquer  for  Steel. — A  good  lacquer  for  steel  is  prepared  by  dis¬ 
solving  io  parts  of  pure  mastic,  5  of  camphor,  15  of  sandarac,  and 
5  of  elemi  in  pure  alcohol,  and  filtering  the  solution.  The  lacquer 
is  used  cold  ;  it  dries  clear  and  transparent. 

Lacquer  for  Tinfoil. — Dissolve  7  ozs.  of  shellac  in  1  quart  of 
alcohol,  and  filter  the  solution.  Allow  the  slime  remaining  upon 
the  filter  to  drain  off,  covering  the  funnel  with  a  glass  plate  to  pre¬ 
vent  as  much  as  possible  the  evaporation  of  alcohol.  To  the  shel¬ 
lac  varnish  thus  obtained  add  3J4  ozs.  of  best  white  gum  elemi  and 
14  drachms  of  Venetian  turpentine,  and  let  the  whole  stand  in  a 
moderately  warm  place,  stirring  frequently.  Then  filter,  press  out 
the  residue,  consisting  almost  entirely  of  gum  elemi,  and  add  it 
to  the  filtrate.  The  varnish  thus  obtained  may  be  colored  as 
desired. 

Metallic  Gold  Color. — Metallic  articles  coated  with  a  very  fine 
gold  varnish  are  frequently  brought  into  commerce  from  France  and 
England.  This  varnish  consists,  according  to  Hart,  of  a  very  soft, 
almost  liquid  amalgam  of  1  part  of  zinc  and  12  parts  of  mercury. 
This  amalgam  is  diluted  with  hydrochloric  acid,  and  the  copper 
articles  are  boiled  in  the  mixture  ;  they  are  then  washed  in  clean 
water  and  dried  in  saw-dust.  The  articles  to  be  varnished  must 
previously  be  carefully  cleansed  with  dilute  nitric  acid. 

To  Lacquer  Optical  Lnstrumenls. — Before  lacquering  the  brass 
must  receive  the  highest  possible  finish  and  polish.  This  is  done 
by  taking  out  the  marks  of  the  file  with  finer  and  finer  sorts  of 
emery  cloth  or  paper,  then  polishing  with  rotten-stone  or  oil,  and 
giving  the  article,  after  this  has  been  cleaned  off,  a  final  touch  with 
a  buff-stick  and  jewelers’  rouge.  The  article  must  be  carefully 
wiped  clean,  and  care  taken  that  it  is  not  touched  afterwards  with 


LACQUERS,  PAINTS  AND  VARNISHES. 


405 


the  fingers,  as  these  would  leave  a  greasy  mark.  Care  must  be 
taken  at  every  step  to  invariably  lay  the  successive  strokes  of  the 
emery  cloth  or  paper  and  polishers  in  the  same  direction.  When 
the  desired  degree  of  polish  has  been  attained,  a  quantity  of  lacquer 
is  poured  into  a  convenient  vessel.  A  fine,  flat  camel’s-hair  brush 
is  taken,  and  the  article  being  gently  warmed  and  held  on  the  left 
hand,  a  small  quantity  of  the  lacquer  is  taken  up  on  the  brush,  and 
the  brush  is  drawn  over  the  brass  with  straight  strokes,  always,  if 
possible,  in  the  same  direction.  The  article  may  generally  be  held 
by  screwing  a  piece  of  wire  into  some  hole  in  it,  and  holding  the 
wire  with  a  small  hand-vise.  As  many  coats  of  the  lacquer  as 
desired  may  be  given  by  keeping  the  brass  hot.  The  degree  of  heat 
is  an  important  element  in  the  success  of  the  operation  ;  it  must  not 
exceed  the  temperature  of  boiling  water,  and  in  some  cases  this 
would  be  too  great.  Considerable  skill  is  required  in  lacquering 
well,  and  that  skill  can  only  be  attained  after  a  great  deal  of  expe¬ 
rience.  The  great  secret  of  lacquering  for  beginners  is  to  take  as 
little  as  possible  of  the  lacquer  at  a  time  on  the  brush,  have  the 
article  perfectly  clean,  a  good  brush  with  no  loose  hairs  in  it,  and 
not  make  the  article  too  hot. 

What  has  been  described  in  the  foregoing  is  the  process  adopted 
for  lacquering  the  outside  of  photographic  lens  mounts,  or  all  those 
portions  of  the  brass  work  where  the  light  does  not  pass.  The 
inside  of  the  mounts,  however,  is  treated  in  an  entirely  different 
way.  Where  the  light  passes  there  must  be  a  surface  as  nearly  dead 
black  as  can  be  got.  This  is  obtained  in  the  inside  of  the  tubes  by 
mixing  finely  triturated  lampblack  with  the  lacquer  used  for  the  out¬ 
side,  and  applying  the  black  lacquer  in  one  or  more  coats  with  heat 
to  the  inside  of  the  tube.  The  result  is  a  finely  grained  black  sur¬ 
face  which  reflects  no  light.  As  soon  as  the  surface  has  received 
one  or  two  coats  no  more  must  be  given,  as  the  repeated  application 
of  the  lacquer  would  make  the  surface  glossy,  the  very  thing  which 
it  is  wished  to  avoid.  This  method  of  blackening  the  brass  does 
excellently  for  all  portions  which  are  not  to  come  in  contact  with 
the  fingers ;  but  wherever  the  brass  requires  to  be  handled  recourse 
must  be  had  to  something  different  from  lampblack.  .  Nitrate  of 


406 


TITE  METAL  WORKER’S  HANDY-BOOK. 


copper  may  be  especially  recommended  for  this  purpose.  A  solu¬ 
tion  is  prepared  by  dissolving  copper  wire  in  nitric  acid,  weakened 
by  adding  3  or  4  parts  of  water  to  1  of  acid.  The  article  to  be 
blackened  is  heated  pretty  hot,  and  then  dipped  into  the  solution ; 
it  is  then  taken  out  and  heated  over  a  Bunsen  burner  or  spirit  lamp. 
When  the  article  is  heated  to  the  proper  temperature  the  green  color 
of  the  copper  first  appears,  and,  as  the  heat  is  increased,  the  article 
becomes  a  fine  dead-black.  It  is  not  necessary  to  lacquer  it,  it 
being  best  to  give  it  simply  a  good  brushing  to  remove  the  dust,  when 
it  may  be  considered  finished.  The  color  becomes  blacker  by  the 
application  of  a  single  coat  of  lacquer,  provided  it  is  not  put  on  in 
sufficient  quantity  to  make  the  surface  glisten — too  much  lacquer, 
however,  invariably  produces  an  objectionable  polished  surface. 

Coating  for  Bars  of  Spring  Steel  no t  Acted  Upon  by  Acids,  Alka¬ 
lies,  etc. — The  bars  are  first  coated  with  copal  or  asphalt  lacquer, 
and  dried  at  a  high  temperature.  They  are  then  wrapped  in  sev¬ 
eral  layers  of  strongly-pressed  paper  impregnated  with  chromium 
glue,  and  subjected  to  a  very  heavy  pressure,  and  finally  receive  a 
coat  of  the  following  compound:  China  clay,  50  parts;  shellac, 
10;  sandarac,  8 ;  elemi,  3  ;  gun  cotton,  2  ;  camphor,  y2  ;  and  oil 
of  lavender,  5,  dissolved  in  100  of  alcohol.  When  half  dry,  the 
bars  are  again  subjected  to  pressure,  and,  when  entirely  dry, 
ground. 

Black  Coating  for  Iron. — To  protect  iron  as  cheaply  as  possible 
from  atmospheric  influences,  it  is  to  be  coated  with  ozokerite. 
Ozokerite  forms  a  brown,  resinous  mass  and  melts  at  about  140°  F. 
For  lacquering  iron  articles  the  ozokerite  is  melted  in  a  kettle,  and 
the  melted  mass  heated  to  about  the  boiling  point  of  water.  The 
sheets  to  be  lacquered,  which  are  to  be  previously  scoured  bright 
by  rubbing  with  sand,  are  immersed  in  the  melted  mass,  and  after 
draining  off,  the  ozokerite  is  ignited  by  holding  the  sheets  over  a 
coal  fire.  After  the  ozokerite  has  burned  for  some  time  the  flame 
extinguishes,  generally  by  itself,  and  the  iron  appears  provided  with 
very  firmly  adhering  black  coating  which  perfectly  resists  all 
atmospheric  influences,  and  also  the  action  of  acids  and  alkaline 
bodies.  If  the  iron  is  to  be  used  for  vessels  for  the  reception  of 


LACQUERS,  PAINTS  AND  VARNISHES. 


407 


alkaline  fluids,  it  is  recommended  to  repeat  the  lacquering  in  the 
manner  described. 

New  Rust  Preventive. — For  the  preparation  of  this  preventive 
the  crude  oils  obtained  in  the  dry  distillation  of  brown  coal,  peat 
or  other  bituminous  substances  are,  according  to  Dr.  L.  Beckert, 
subjected  to  a  second  distillation.  The  distillate  passing  over  at 
482°  to  5720  F.  forms  the  initial  point  for  the  process.  Caout¬ 
chouc  rolled  out  thin  and  cut  into  strips  is  poured  over  with  four 
times  its  quantity  of  this  oil  and  allowed  to  stand  for  8  days, 
whereby  it  is  converted  into  a  homogeneous  and  soft  mass  which 
can  be  drawn  into  threads.  This  mass  is  worked  by  means  of  a 
stirring  apparatus  with  pale  vulcan  oil  or  other  suitable  hydro¬ 
carbon  until  a  homogeneous,  clear  fluid  drawing  threads  is  formed. 
In  this  manner  the  mechanical  incorporation  of  the  caoutchouc 
with  the  oil  is  effected  without  a  separation  afterwards  taking  place. 
By  applying  the  oil  in  as  thin  a  layer  as  possible  by  means  of  a 
flannel  rag  to  a  metallic  surface,  and  drying  slowly,  a  thin  film  of 
caoutchouc  oil  is  formed  which  affords  an  absolute  protection 
against  atmospheric  influences.  After  exposure  for  one  year  not 
the  slightest  cracks,  it  is  claimed,  could  be  detected  in  the  film  of 
oil  even  by  a  microscopical  examination.  To  remove  the  oil  the 
articles  are  thoroughly  oiled  with  caoutchouc  oil ;  after  allowing 
the  latter  to  act  for  12  to  24  hours,  the  clean  metallic  surface  is 
restored  by  wiping  off.  It  is  claimed  that  the  caoutchouc  oil  is 
also  especially  adapted  for  loosening  rust  already  present. 

To  Protect  Iron  and  Steel  from  Rust. — The  following  method  is 
but  little  known,  although  it  deserves  preference  over  many  others: 
Add  1 pints  of  cold  water  to  7  ozs.  of  quick  lime.  Let  the  mix¬ 
ture  stand  until  the  supernatant  fluid  is  entirely  clear.  Then  pour 
this  off  and  mix  it  with  enough  olive  oil  to  form  a  thick  cream,  or 
rather  to  the  consistency  of  melted  and  recongealed  butter.  Grease 
the  articles  of  iron  or  steel  with  this  compound,  and  then  wrap 
them  up  in  paper,  or,  if  this  cannot  be  done,  apply  the  mixture 
somewhat  more  thickly. 

To  Protect  Lightning-rods,  Metal  Roofs,  etc.,  from  Rust. — Con¬ 
vert  2  parts  of  graphite  mixed  with  8  parts  of  sulphide  of  lead  and 


408 


TTIE  METAL  WORKER’S  HANDY-BOOK. 


2  of  sulphate  of  zinc  into  an  impalpable  powder,  and  add  gradually 
30  parts  of  linseed  oil  varnish  previously  heated  to  the  boiling 
point.  This  varnish  dries  very  quickly,  and  protects  the  metals 
coated  with  it  from  oxidation. 

To  Protect  Lead  Pipes  it  is  recommended  to  provide  them  with 
a  coat  of  sulphide  of  lead.  Dissolve  y2  oz.  of  caustic  soda  in  iy 
quarts  of  water ;  mix  the  solution  with  one  of  y2  of  lead  nitrate  (or 
an  equivalent  of  another  lead  salt  soluble  in  water)  in  y2  pint  of 
Avater,  and  heat  the  mixture  to  1 95 0  F.  As  soon  as  a  sufficient 
quantity  of  lead  salt  has  been  added  the  fluid  becomes  turbid,  and 
must  be  quickly  filtered  through  asbestus  or  a  similar  material.  To 
the  clear  fluid  add  2 y2  ozs.  of  hot  water  containing  1  drachm  of 
sulphocarbonide  in  solution.  In  using  the  fluid  it  is  best  to  heat 
it  to  150°  F.,  and  to  hold  the  thoroughly  cleansed  lead  pipe  in  it 
for  a  few  moments,  when  it  will  be  quickly  coated  with  a  fine  layer 
of  sulphide  of  lead.  If  the  lead  has  been  thoroughly  cleansed  the 
sulphide  of  lead  adheres  very  tenaciously  and  can  be  polished  with 
a  piece  of  leather. 

Painting  of  Iron. — On  exposure  to  the  atmospheric  air  all  metals 
soon  lose  their  metallic  lustre  ;  they  oxidize  by  absorbing  oxygen 
from  the  air.  Iron  becomes  coated  with  a  layer  of  hydrated 
sesquioxide  of  iron  or  rust ;  copper  with  carbonate  of  copper  as 
well  as  with  the  hydrate,  while  zinc  also  oxidizes  very  rapidly,  it 
becoming  dull  gray.  This  change  takes  place  most  rapidly  in 
iron,  every  drop  of  rain  causing  a  rust  stain,  and,  hence,  only  iron 
perfectly  free  from  rust  can  be  successfully  painted.  When  the 
oxidizing  process  has  once  commenced,  its  progress  may  for  a  time 
be  interrupted  by  painting,  but  it  progresses  slowly  even  under  the 
paint,  the  latter  finally  peeling  off  together  with  the  layer  of  rust. 
Copper  oxidizes,  but  so  slowly  that  protecting  agents  are  seldom 
used.  While,  when  applied  to  wood,  the  paint  penetrates  the 
pores,  thus  allowing  of  an  intimate  mechanical  union,  it  cannot 
penetrate  the  fine  pores  of  the  metals  and,  hence,  the  protection  it 
offers  consists  simply  of  a  protecting  coat,  and  consequently  a 
paint  entirely  different  from  that  used  for  wood  is  required  for 
iron.  The  principal  point  in  painting  iron  is  the  priming  color. 


LACQUERS,  PAINTS  AND  VARNISHES. 


409 


If  this  is  defective  or  incorrectly  applied  the  efficacy  of  the  entire 
work  is  doubtful,  even  if  the  succeeding  coats  are  correctly  applied, 
because  in  such  a  case  a  union  between  the  priming  and  body 
colors  only  takes  place,  which,  if  the  former  does  not  firmly 
adhere  to  the  iron,  soon  becomes  full  of  cracks  and  scales  off.  For 
the  priming  color  to  adhere  firmly  to  the  iron  three  conditions  are 
required  :  i,  it  must  be  capable  of  drying  quickly  and  thoroughly; 
2,  it  must  be  thinly-fluid  ;  and  3,  it  must  be  applied  in  a  thin  layer 
only.  The  priming  color  should  dry  quickly,  so  that  by  the  lower¬ 
ing  of  the  temperature  with  a  content  of  moisture  remaining  in 
the  air,  which  occurs  quite  frequently,  and,  as  a  rule,  toward  even¬ 
ing,  a  precipitate  of  atmospheric  water  is  not  formed  upon  the  iron 
before  the  paint  has  become  solid.  A  sort  of  emulsion  of  the 
paint  takes  place  thereby,  in  consequence  of  which  it  never  dries  to 
a  solid,  homogeneous  mass.  If  the  iron  is  painted  in  the  open  air 
a  precipitate  of  moisture  may  also  be  formed  upon  it  by  the  radiation 
of  heat  from  the  iron.  The  power  of  the  radiating  heat  of  iron,  as 
well  as  of  metals  in  general,  is,  to  be  sure,  small,  but  Mellam’s  ex¬ 
periments  have  shown  that  it  increases  considerably  when  the 
metallic  surface  is  coated  with  varnish. 

The  priming  color  should  be  thinly-fluid  in  order  to  be  sure  that 
all  inequalities  of  the  surface  to  be  painted  may  be  covered.  If  a 
mistake  is  made  in  this  direction,  as  frequently  happens  when  the 
paint  is  too  thick  and  the  painter  is  not  very  careful,  the  coating 
readily  tears  under  the  expansion  of  the  metallic  surface  by  heat, 
air  and  moisture  penetrating  into  the  fissures  and  gradually  under¬ 
mining  the  entire  coat  of  paint  by  the  formation  of  rust.  And, 
finally,  the  layer  of  paint  should  be  very  thin,  because  paints  on 
iron  and  other  non-porous  surfaces  dry  very  slowly.  If  a  thick 
layer  is  applied,  only  a  film  is  formed  on  top,  under  which  the  paint 
remains  fluid  for  a  long  time. 

Paint  for  Sheet-iron  Roofs. — The  priming  color  is  linseed  oil 
with  red-lead  ;  for  painting  use  1  part  of  verdigris,  1  of  white-lead, 
and  3  of  linseed  oil;  or,  y2  of  verdigris,  i~y  of  white-lead  and 
2 y2  of  linseed  oil.  The  sheet-iron  receives  three  coats,  the  first 


410 


TOE  METAL  WORKER’S  IIANDY-ROOK. 


before  it  is  used,  the  second  after  the  first  is  thoroughly  dry,  and 
the  third  three  days  later. 

Paint  for  Preserving  Zinc  Roofs. — Fat  or  resinous  paints  for 
zinc  roofs  must  be  prepared  with  an  abundant  content  of  copper  by 
the  actual  chemical  solution  of'  suitable  copper  preparations  in  the 
varnishes  and  oils.  Such  paints  combine  very  intimately  with  the 
zinc  surfaces,  so  that  they  resist  the  most  abrupt  changes  of  tem¬ 
perature  without  scaling  off.  For  the  preparation  of  such  paints 
either  copper  soap  prepared  by  precipitating  a  solution  of  copper 
salt  with  soap  solution  is  dissolved  in  varnish,  or  the  emulsion,  like 
Russian  train-oil  paint,  mixed  with  solution  of  copper  salt.  Rus¬ 
sian  train-oil  paint  is  prepared  by  mixing  train-oil  with  a  solution 
of  soda  or  potash  and  suitable  mineral  colors,  so  that  a  thinly- 
fluid  paint  is  formed. 

Puscher  claims  to  have  found  a  simple  process  of  applying  a  very 
durable  paint  of  various  colors  to  sheet-zinc.  It  is  based  upon  the 
use  of  basic  acetate  of  lead.  To  a  solution  of  this  salt  colcothar 
may,  for  instance,  be  added,  the  result  being  a  very  agreeable, 
brown-red  paint.  Such  paint  was  used  for  painting  the  five  domes 
of  the  Niirnberg  synagogue.  By  adding  other  coloring  substances 
light,  dark  and  gray  colors  as  well  as  yellowish  shades  can  be 
obtained,  and  thus  zinc  castings  used  for  architectural  purposes 
may  be  given  the  appearances  of  sculptured  work. 

Black  Varnish  for  Iron  and  Steel. — A  black  varnish  of  a 
splendid  tone  is  produced  on  steel  and  iron  by  turpentine  and 
sulphur  boiled  together,  laid  on  with  a  brush.  The  evaporation 
of  the  turpentine  leaves  a  thin  layer  of  sulphur,  which  unites  with 
the  iron  when  heated  a  short  time  over  a  gas  or  spirit  flame.  The 
varnish  is  durable  and  perfect. 

Black  Varnish  for  Zinc. — Dissolve  equal  parts  of  chlorate  of 
potash  and  blue  vitriol  in  36  times  as  much  warm  water  and  allow 
the  solution  to  cool.  If  the  blue  vitriol  used  contains  iron,  it  is 
precipitated  as  a  hydrated  oxide,  and  can  be  removed  by  decanta¬ 
tion  or  filtration.  The  zinc  castings  are  then  immersed  for  a  few 
seconds  in  the  solution  until  quite  black,  rinsed  off  in  water  and 
dried.  Even  before  it  is  completely  dry  the  black  coating  adheres 


LACQUERS,  PAINTS  AND  VARNISIIES. 


41 L 


to  the  article  so  that  it  may  be  wiped  dry  with  a  cloth.  If  copper- 
colored  spots  appear  during  the  operation  the  solution  is  applied 
to  them  a  second  time,  and  after  a  while  they  turn  black,  when  the 
article  is  washed  and  dried.  On  rubbing  the  coating  acquires  a 
glittering  appearance  like  indigo,  which  disappears  on  applying 
a  few  drops  of  linseed  oil  varnish  or  “wax  milk,”  and  the  zinc* 
then  has  a  deep-black  color  and  gloss.  The  “wax  milk”  is  pre¬ 
pared  by  boiling  i  part  of  yellow  soap  and  5  of  Japanese  wax  in 
21  of  water  until  the  soap  dissolves.  When  cold  it  has  the  con¬ 
sistency  of  a  salve,  and  will  keep  in  closed  vessels  for  an  indefinite 
time. 

Bright  Asphalt  Varnish  for  Sheet  Metals. — Boil  coal-tar  until  it 
shows  a  disposition  to  harden  on  cooling;  this  can  be  ascertained 
by  rubbing  a  little  on  a  piece  of  metal.  Then  add  about  20  per 
cent,  of  lump  asphalt,  stirring  it  with  the  boiling  coal-tar  until  all 
the  lumps  are  melted,  when  it  is  allowed  to  cool  and  kept  for  use. 

Colored  Varnish  for  Sheet  Metal. — Rub  7  y2  drachms  of  acetate  of 
copper  to  a  fine  powder  in  a  mortar,  spread  the  powder  in  a  thin 
layer  upon  a  porcelain  plate,  and  let  it  stand  in  a  moderately  warm 
place.  In  a  few  days  the  water  of  crystallization  and  most  of  the 
acetic  acid  will  be  evaporated.  Triturate  the  light-brown  powder 
which  remains  behind  with  some  oil  of  turpentine,  and  stir  in 
ozs.  of  a  fine  quality  of  fat  copal  varnish  heated  to  167°  F.  If  the 
acetate  of  copper  has  been  rubbed  extraordinarily  fine,  the  larger  por¬ 
tion  of  it  will  be  dissolved  after  stirring  hour.  The  varnish  is 
then  poured  into  a  glass  bottle,  placed  in  a  warm  place,  and 
frequently  shaken.  The  small  quantity  of  acetate  of  copper  which 
settles  on  the  bottom  may  be  used  in  the  preparation  of  further  por¬ 
tions  of  varnish.  This  varnish  is  dark  green  ;  four  to  five  coats  are 
required  to  produce  a  beautiful  green  lustre  upon  articles  of  sheet 
metal ;  but  in  order  to  obtain  a  variety  of  gold  shades  two  coats  are 
sufficient  if  the  respective  articles  are  heated  in  a  drying  chamber  or 
upon  uniformly  heated  metal  plates.  According  to  the  time  of 
heating,  either  a  greenish  or  yellow  shade,  or  a  dark  yellow,  orange 
or  reddish  brown  may  be  obtained.  These  colors  surpass  in  lustre 
those  produced  with  English  gold  varnish,  and  have  the  advantage 


412 


THE  METAL  WORKER'S  HANDY-BOOK. 


of  remaining  constant  on  exposure  to  light.  If  a  good  quality  of 
copal  varnish  is  used  in  the  preparation  of  a  polychromatic  varnish 
or  lacquer,  the  sheet  metal  may  even  be  hammered.  The  produc¬ 
tion  of  gold  colors  depends  on  the  reduction  of  oxide  of  copper,  it 
yielding  a  gold  color  when  dissolved  in  small  quantity  by  the  copal 
varnish.  The  more  heat  is  applied  the  greater  the  reduction  which 
takes  place,  and  hence  the  darker  color. 

Green  Varnish  for  Metals. — Dissolve  finely  pulverized  gum  san- 
darac  or  mastic  in  strong  potash  lye  until  it  will  dissolve  no  more. 
Dilute  the  solution  with  water  and  precipitate  it  with  a  solution  of 
copper  salt,  either  sulphate  or  acetate.  The  green  precipitate  is 
washed,  dried,  and  dissolved  in  oil  of  turpentine,  producing  a  fine 
green  varnish,  which  does  not  change  under  the  effect  of  light,  and 
is  especially  useful  for  ornamental  iron  work. 

Green  Transparent  Varnish. — Grind  a  small  quantity  of  Chinese 
blue  with  double  the  quantity  of  finely  powdered  chromate  of  pot¬ 
ash,  add  a  sufficient  quantity  of  copal  varnish,  thinned  with  turpen¬ 
tine.  The  tone  may  be  altered  by  more  or  less  of  one  or  the  other 
ingredients. 

Varnish  for  Iron  Work. — Dissolve  in  about  2  lbs.  of  tar  oil 
lb.  of  asphalt  and  a  like  quantity  of  pounded  resin,  mix  hot  in  an 
iron  kettle,  care  being  taken  to  prevent  any  contact  with  the  flame. 
When  cold  the  varnish  is  ready  for  use.  This  varnish  is  for  out¬ 
door  wood  and  iron  work. 

Varnish  for  Common  Work. — This  varnish  is  intended  for  pro¬ 
tecting  surfaces  against  atmospheric  influences.  It  has  been  used 
for  coating  wood  and  iron  work  with  great  advantage.  Take  3  lbs. 
of  resin  and  powder  it,  place  it  in  a  tin  can,  and  add  2^/2  pints  of 
spirits  of  turpentine,  shake  well,  and  let  it  stand,  occasionally 
agitating  it,  for  a  day  or  two.  Then  add  of  boiled  linseed  oil  5 
quarts,  shake  the  whole  together,  and  allow  it  to  stand  in  a 
warm  room  till  clear.  The  clear  portion  is  decanted  and  used,  or 
reduced  with  spirits  of  turpentine  until  of  the  proper  consistency. 

Varnish  for  Iron  Patterns. — Add  to  oil  of  turpentine,  drop  by 
drop,  strong  commercial  sulphuric  acid ;  the  acid  will  cause  a  dark 
syrupy  precipitate  in  the  oil  of  turpentine;  keep  adding  drops  of 


SOLDERING  AND  SOLDERS. 


413 


sulphuric  acid  until  no  more  precipitate  is  formed  ;  then  pour  out 
the  liquid  and  wash  the  syrupy  mass  with  water,  and  it  is  ready  for 
use.  Heat  the  iron  to  be  varnished  to  a  moderate  heat,  apply  the 
syrupy  product,  and  allow  it  to  dry. 

Varnish  for  Metals  According  to  Max  Innes. — Potash  or  soda  soap 
is  decomposed  by  a  metallic  salt — best  sulphate  of  zinc.  The  me¬ 
tallic  soap  thus  formed  is  purified  by  washing,  and,  after  adding  io 
per  cent,  of  tallow,  the  whole  is  diluted  with  petroleum  or  another 
volatile  oil,  which  dissolves  the  metallic  soap.  It  is  then  filtered 
until  entirely  bright  and  clear,  and  kept  for  use  in  well-closed 
vessels. 


XIV. 

SOLDERING  AND  SOLDERS. 

Soldering  is  the  process  of  uniting  the  edges  or  surfaces  of  sim¬ 
ilar  or  dissimilar  metals  and  alloys  by  partial  fusion.  In  general 
alloys  or  solders  of  various  and  greater  degrees  of  fusibility  than  the 
metals  to  be'  joined  are  placed  between  them,  and  the  solder  when 
fused  unites  the  three  parts  into  a  solid  mass.  Less  frequently  the 
surfaces  or  edges  are  simply  melted  together  with  an  additional  por¬ 
tion  of  the  same  metal.  The  solders  are  broadly  distinguished  as 
hard  solders  and  soft  solders ;  the  former  only  fuse  at  a  red  heat, 
and  are  consequently  suitable  alone  to  metals  and  alloys  which  will 
endure  that  temperature ;  the  soft  solders  melt  at  very  low  degrees 
of  heat,  and  may  be  used  for  nearly  all  the  metals. 

The  attachment  is  in  every  case  the  stronger  the  more  nearly  the 
metals  and  solders  respectively  agree  in  hardness  and  malleability. 
Thus,  if  two  pieces  of  brass  or  copper,  or  one  of  each  are  brazed 
together,  or  united  with  spelter-solder — an  alloy  nearly  as  tough  as 
the  brass — the  work  may  be  hammered,  bent,  and  rolled  almost  as 
freely  as  the  same  metals  when  not  soldered,  because  of  the  nearly 
equal  cohesive  strength  of  the  three  parts.  Lead,  tin,  or  pewter 
are  also  malleable  from  the  near  agreement  of  these  substances; 


414 


THE  METAL  WORKER’S  IIANDY-BOOK. 


whereas,  when  copper,  brass,  and  iron  are  soft-soldered,  a  blow  of 
the  hammer,  or  any  accidental  violence,  is  almost  certain  to  break 
the  joint  asunder  so  long  as  the  joint  is  weaker  than  the  metal  gen¬ 
erally  ;  and,  therefore,  the  joint  is  only  safe  when  the  surrounding 
metal,  from  its  thinness,  is  no  stronger  than  the  solder,  so  that  the 
two  may  yield  in  common  to  any  disturbing  cause. 

In  hard-soldering  it  is  frequently  necessary  to  bind  the  works 
together  in  their  respective  positions ;  this  is  done  with  soft  iron 
binding  wire  which  for  delicate  jewelry  work  is  exceedingly  fine, 
and  for  stronger  work  is  ^  or  ^  -inch  in  diameter.  It  is  passed 
around  the  work  in  loops,  the  ends  of  which  are  twisted  together 
with  the  pliers.  In  soft  soldering  the  binding  wire  is  scarcely  ever 
used,  as,  from  the  moderate  and  local  application  of  the  heat,  the 
hands  may  generally  be  freely  used  in  retaining  most  of  thin  work 
in  position  during  the  process.  Thick  work  is  handled  with 
pliers  or  tongs  whilst  being  soft-soldered,  and  is  often  treated 
much  like  glue  joints,  if  we  conceive  the  wood  to  be  replaced  by 
metal,  and  the  glue  by  solder,  as  the  two  surfaces  are  frequently 
coated  or  tinned  whilst  separated,  and  then  rubbed  together  to 
distribute  and  exclude  the  greater  part  of  the  solder. 

For  the  soft  solders,  the  soldering  iron  is  the  most  general  agent 
for  applying  the  heat;  for  the  hard  solder,  forge  or  other  fires,  or 
the  blow-pipe,  are  generally  adopted.  Brazing  (used  with  sheet 
brass  and  sheet  copper)  may  be  defined  as  soldering  with  fusible 
brass,  and  hence  as  a  form  of  hard  soldering. 

The  soldering  iron — more  correctly  the  copper  soldering  bit — 
consists  of  a  small  piece  of  solid  copper  rivetted  between  the  forked 
end  of  a  split  iron  rod,  the  whole  being  provided  with  a  wooden 
handle.  All  works  in  tinned  and  sheet  iron,  and  many  of  those  in 
copper  and  brass,  are  soldered  with  the  copper-bit,  which  in  general 
suffices  to  convey  all  the  heat  required  to  melt  the  more  fusible 
solders  now  employed.  If  the  copper-bit  has  not  been  previously 
tinned,  it  is  heated  in  a  small  charcoal  stove,  or  otherwise,  to  a 
dull  red,  and  quickly  filed  to  a  clean  metallic  surface;  it  is  then 
rubbed  immediately,  first  upon  a  lump  of  sal-ammoniac,  and  next 
upon  a  copper  or  tin  plate  upon  which  a  few  drops  of  solder  have 


SOLDERING  AND  SOLDERS. 


415 


been  placed.  This  will  completely  coat  the  tool ;  it  is  then  wiped 
clean  with  a  piece  of  tow  and  is  ready  for  use. 

The  copper-bit  or  end  must  always,  as  has  been  said,  be  tinned, 
or  covered  with  tin,  before  using.  This  always  needs  to  be  done. 
Here  is  another  plan  :  File  it  bright  with  a  fine  file,  and  give  it  a 
pointed  end,  not  too  sharp,  and  then  put  it  into  your  charcoal  or 
coke  fire.  Get  a  soft  red  brick  and  scoop  out  a  hole  as  big  as  a 
cherry  in  its  top  surface.  When  the  bit  is  not  quite  red  hot,  hold 
the  bar  of  solder  in  your  left  hand  over  the  hole  in  the  brick,  and 
touch  it  with  the  hot  bit  in  such  a  way  that  the  metal  drops  into  the 
cavity;  drop  also  a  pinch  of  powdered  resin  on  it.  Now  rub  the 
bit  round  and  round  in  the  brick  until  it  gets  cool,  and  by  that 
time,  if  the  operation  has  been  properly  performed,  it  will  be  coated 
with  solder. 

It  is  customary  to  keep  two  soldering  irons  in  use,  so  that  while 
one  is  in  hand  the  other  may  be  heating  in  the  stove.  It  is  im¬ 
possible  to  make  satisfactory  work  unless  the  tool  be  kept  at  a 
sufficient  heat.  It  should  not,  however,  be  raised  to  too  great  a 
heat  or  the  tinning  will  be  burned  off  and  will  need  to  be  re¬ 
placed. 

Besides  the  usual  copper-bit  the  plumber  employs  a  large  heavy 
bulbous  iron  in  soldering.  This  is  especially  used  for  joints  in 
lead  pipe,  which  require  to  be  very  sound.  These  are  generally 
extremely  clumsy  in  appearance,  as  by  the  aid  of  the  hot  iron  and 
a  piece  of  tick  held  in  the  left  hand  the  plumber  manages  to 
plaster  a  great  bulbous  patch  of  solder  round  the  point  of  junction, 
which  is  termed  a  “  wiped"  joint. 

The  blow-pipe  (mouth)  is  used  to  some  extent  in  soft  soldering, 
principally  by  the  gas-fitter,  who  is  generally  remarkably  expert  in 
making  therewith  joints  in  his  composition  pipes.  These  are  not 
made  like  the  plumber’s,  by  inserting  one  end  of  the  pipe  in  the 
other  and  plastering  a  bulb  of  solder  around  the  place,  but  by 
cutting  off  the  pipes  with  a  fine  saw  and  filing  them  up  square  and 
smooth  to  butt  together  into  a  mitre  or  T  joint.  These  joints 
have  frequently  to  be  made  in  very  awkward  and  confined  situa¬ 
tions  amongst  joists  under  floors,  etc.,  and  are  generally  effected 


416 


THE  METAL  WORKER’S  HANDY-BOOK. 


by  applying  the  heat  from  one  side  only,  by  holding  a  small  bundle 
of  dried  ignited  rushes  there  and  forcing  the  flame  thus  obtained 
upon  the  joints  with  a  blow-pipe.  They  generally  use  a  solder 
rich  in  tin,  and  employ  a  flux  of  oil  and  resin  in  equal  parts. 

The  pewterers  generally  use  the  hot-air  blast  by  means  of  a 
peculiar  apparatus  employed  only  in  their  trade.  They  use  fusible 
solder  containing  bismuth,  and  for  flux  a  common  green  olive  oil, 
termed  Gallipoli  oil. 

For  hard  soldering  an  intense  fire  heat  is  required,  similar  to 
that  obtained  in  the  smith’s  forge.  In  fact  the  ordinary  black¬ 
smith’s  forge  is  frequently  used  for  brazing,  although  the  process  is 
injurious  to  the  fuel  as  concerns  its  normal  purpose.  The  brazier’s 
hearth,  for  extensive  work,  is  generally  a  plate  of  iron  about  4  X 
3  feet,  supported  on  four  legs  at  its  corners,  and  with  a  central 
opening  about  2  feet  by  1  foot,  and  6  inches  deep  for  the  fuel. 
The  blast  is  generally  supplied  by  a  fan,  and  the  tuyere-irons  have 
large  apertures. 

Fresh  coal  should  never  be  used,  but  charcoal,  or,  failing  that, 
coke  or  cinders.  Lard  in  the  fire  is  very  prejudicial. 

In  all  cases  of  hard-soldering  or  brazing  the  meeting  edges  are 
to  be  scraped  or  filed  clean,  especially  when  the  heat  used  will  not 
reach  the  red  degree.  The  work  in  copper,  iron,  brass,  etc., 
having  been  prepared  and  the  joints  retained  in  position  by  bind¬ 
ing  with  iron  wire  when  needed,  the  granulated  spelter  and  borax 
are  mixed  in  a  cup  with  a  very  little  water,  and  spread  along  the 
joints  by  a  slip  of  sheet-metal  or  a  small  spoon.  The  work  is  then 
placed  above  the  clear  fire,  first  at  a  small  distance,  gradually  to 
evaporate  the  moisture  and  deprive  the  borax  of  its  water  of 
crystallization.  During  this  process  the  flux  boils  up  with  a  frothy 
appearance,  and  sometimes  shifts  the  solder  away.  The  heat  is  now 
increased,  and  when  the  metal  assumes  a  faint  red  the  borax  melts 
like  glass.  As  the  metal  becomes  deeper  red  the  solder  also  fuses, 
generally,  if  it  contains  any  zinc,  with  a  slight  blue  flame.  Gener¬ 
ally  at  this  point  the  solder  “  flushes”  or  disappears  in  the  work. 
Should  it  not  do  so,  and  appear  refractory  on  the  score  of  running 
into  the  joint,  the  work  may  be  tapped  with  the  tongs  in  order  to 


SOLDERING  AND  SOLDERS. 


417 


make  it  move.  Care  must,  of  course,  be  taken  that  the  heat  is  not 
so  much  raised  as  to  melt  the  work  as  well  as  the  solder.  If  the 
work  be  iron,  there  is,  of  course,  little  need  of  precaution. 

If  iron  is  to  be  brazed  the  meeting  surfaces  must  be  filed  bright. 
Make  a  little  borax  into  a  paste  with  water  and  smear  them  over 
with  this.  Next  tie  them  together  with  fine  iron  wire ;  just  enough 
to  prevent  the  pieces  from  coming  apart.  Then  wind  them  round 
and  round  at  the  place  of  the  joint  with  several  coils  of  fine  brass 
wire,  rubbing  them  over  with  the  borax  paste.  This  is  then  laid 
on  the  fire  and  the  blast  put  on.  Presently  a  small  blue  flame  will 
be  seen  reflecting  over  the  place.  This  is  a  sign  that  the  brass 
wire  is  melting  and  the  heat  is  dissipating  the  zinc  constituents  of 
the  brass,  and  the  brass  having  melted  and  run  into  the  joint  the 
job  is  done. 

It  is  only  iron,  however,  to  which  so  much  heat  can  be  applied. 
For  brass  and  copper  a  more  fusible  metal  than  brass  must  be  em¬ 
ployed.  This  solder  is  called  “spelter,”  and  is  composed  of  equal 
parts  of  copper  and  zinc.  In  fact  it  is  a  very  soft  kind  of  brass, 
and  liquefies  at  a  much  lower  temperature  than  copper  or  ordinary 
brass. 

The  blow-pipe  is  largely  used  in  hard  soldering  and  brazing, 
especially  for  work  in  the  precious  metals.  The  ordinary  blow¬ 
pipe  is  a  light  conical  brass  tube  about  10  or  12  inches  long,  from 
J^-inch  to  ^ -inch  in  diameter  at  the  end  for  the  mouth,  and  from 
ts  to  5V'nch  at  the  aperture  or  jet.  The  small  end  is  bent  in  a 
quadrant,  that  the  flame  may  be  immediately  in  sight.  Very 
usually  it  is  fitted  with  a  small  hollow  brass  ball  just  below 
the  quadrant,  to  serve  as  a  receptacle  for  the  condensed  vapor 
from  the  lungs.  This  instrument  is  generally  used  with  a  lamp  of 
a  wick  from  to  1  inch  in  diameter  and  produces  a  flame  of  great 
heat,  the  object  exposed  to  it  being  generally  placed  upon  char¬ 
coal.  Gas  is  frequently  used  in  conjunction  with  the  blow-pipe,  and 
this  is  especially  useful  for  sheet-brass,  the  work  being  held  in  place 
by  wire  ties  if  necessary,  and  either  laid  upon  a  flat  piece  of 
pumice-stone  or  held  in  a  pair  of  pliers. 

Since  soldering  must  be  executed  with  the  assistance  of  heat, 
27 


418 


THE  METAL  WORKER’S  HANDY-BOOK. 


and  the  places  to  be  joined  would  soon  become  again  coated  with 
oxide,  even  if  previously  cleansed,  care  must  be  had  to  either  ex¬ 
clude  the  atmospheric  air  from  the  metal  during  the  operation,  or 
to  dissolve  the  oxides  formed,  or  to  reduce  them  to  metal.  Besides 
various  soldering  liquids,  the  following  substances  are  used  as 
fluxes :  clay,  borax,  powdered  glass,  phosphoric  acid  and  phos¬ 
phates,  cryolite,  hydrochloric  acid,  chloride  of  zinc,  colophony, 
sal-ammoniac  and  soldering  grease.  Clay  is  only  used  for  the 
exclusion  of  the  air,  especially  in  soldering  iron.  Powdered  glass 
excludes  the  air  only  after  fusion,  consequently  when  oxides  have 
already  formed,  which,  however,  dissolve  readily  in  the  fused  glass, 
entering  into  combination  with  the  free  silicic  acid  of  the  glass. 

Hydrochloric  Acid  exerts  a  corroding  and  dissolving  effect  upon 
the  oxides.  It  is  much  used  in  soldering  zinc,  it  not  being  nec¬ 
essary  to  previously  brighten  the  metal.  Still  better  is  a  solution 
of  chloride  of  zinc,  which  may  be  used  for  all  kinds  of  metal. 
When  the  places  to  be  joined  are  free  from  dirt  they  need  not  be 
filed  or  scraped  ;  iron  alone  has  to  be  cleansed,  which  is  readily 
effected  by  brushing  the  places  to  be  soldered  with  hydrochloric 
acid  and  rubbing  with  a  piece  of  sheet-zinc. 

Powdered  Colophony,  turpentine  and  even  oil  of  turpentine  are 
used  as  soldering  agents.  At  the  heat  required  for  soldering  they 
melt  and  decompose,  hydrogen  and  carbon  being  formed.  It  is 
generally  supposed  that  it  is  the  carbon  alone  which  effects  the  re¬ 
duction  of  the  metallic  oxide  formed  on  the  joint  to  be  soldered  ; 
however,  according  to  Spencer’s  experiments,  the  hydrogen  liber¬ 
ated  in  the  distillation  of  resins  also  plays  an  important  part  as  a 
reducing  agent,  and,  therefore,  beeswax  especially  would  be  still 
more  suitable  as  a  soldering  agent. 

The  flux  mostly  used  in  soft  soldering  is  a 

Soldering  Liquid  prepared  as  follows :  Dissolve  small  pieces  of 
zinc  in  pure  hydrochloric  acid  until  effervescence  ceases.  After  a 
few  days  take  out  the  undissolved  zinc,  filter  the  solution,  com¬ 
pound  it  with  yi  its  volume  of  spirits  of  sal-ammoniac,  and  finally 
dilute  with  rain  water.  This  soldering  liquid  causes  no  rust  on  iron 


SOLDERING  AND  SOLDERS. 


419 


or  steel,  and  does  excellent  service  in  all  soldering,  as  well  as  tin¬ 
ning  operations. 

Soldering  Paste. — By  mixing  solution  of  chloride  of  tin  with 
starch  paste  a  syrupy  liquid  is  obtained  which  is  frequently  used  in 
soldering,  it  being  more  readily  applied  to  the  soldering  seam 
than  ordinary  soldering  liquid. 

Soldering  Fat. — Besides  chloride  of  tin,  soldering  fat  is  also  used 
in  soldering  tin-plate,  etc.  It  is  prepared  as  follows :  Melt  in  a 
pot  over  a  gentle  coal-fire  x  lb.  of  olive  oil  and  i  lb.  of  tallow,  and 
after  stirring  in  8  ozs.  of  pulverized  colophony,  allow  the  mass  to 
boil  up.  When  the  mixture  is  sufficiently  cool  add,  with  constant 
stirring,  ^  pint  of  water  previously  saturated  with  pulverized  sal- 
ammoniac,  whereby  the  mass  acquires  a  yellow  color,  and  is  ready 
for  use. 

The  above-mentioned  fluxes  cannot  be  used  for  hard  soldering, 
as  they  would  burn  or  volatilize  at  the  temperature  required.  In¬ 
stead  of  them  borax  or  phosphates  and  occasionally  phosphoric  acid 
are  employed,  these  substances  possessing  in  a  high  degree  the 
power  of  dissolving  metallic  oxides,  and  at  a  high  temperature 
fusing  with  them  together  to  a  glass-like  mass.  They  are  used 
either  in  a  solid  form  or  as  solution.  Ordinary  borax  can  only  be 
used  for  preparing  soldering  liquid,  since,  when  used  dry,  it  loses 
by  heating  its  water  of  crystallization,  swells  up  and  causes  dis¬ 
turbance  in  the  operation.  For  use  in  a  powdered  state  borax  has 
to  be  calcined  ;  this  is  readily  effected  by  heating  ordinary  borax 
until  it  forms  a  readily  friable  mass. 

Phosphoric  acid  is  used  diluted  either  with  water  or  spirits  of 
wine. 

Muller' s  Soldering  Liquid  consists  of  a  solution  of  phosphoric 
acid  in  alcohol.  It  is  prepared  by  dissolving  phosphorus  in  nitric 
acid,  evaporating  the  solution  to  expel  any  excess  of  nitric  acid 
and  mixing  the  syrupy  mass  with  an  equal  quantity  of  strong  alcohol. 
The  phosphoric  acid  dissolves  the  layer  of  oxide,  the  combination 
formed  melting  under  the  soldering  iron,  and  is  displaced  by  the 
melted  solder  which  now  comes  in  contact  with  the  bright  metallic 


420 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


surface.  This  fluid  can  be  advantageously  used  in  soldering  copper, 
as  well  as  brass,  bronze  and  argetan. 

Gauduin's  Soldering  Liquid  for  copper  and  bronze  consists  of  a 
mixture  of  finely  pulverized  cryolite  and  a  solution  of  phosphoric 
acid  in  spirits  of  wine. 

New  Soldering  Liquid. — Dissolve  i  part  each  of  lactic  acid  and 
glycerin  in  8  of  water.  This  liquid  is  claimed  to  possess  the 
advantage  over  zinc  chloride  of  not  being  corrosive,  or  injurious  to 
the  health  of  the  workman. 

Soft  Solders. — The  soft  solder  most  frequently  used  consists  of  2 
parts  of  tin  and  1  of  lead.  A  cheaper  solder  is  formed  by 
increasing  the  proportion  of  lead;  tin  to  1  lead  is  the  most 
fusible  solder  unless  bismuth  be  added.  The  following  table  gives 
the  composition  of  some  of  these  solders  with  their  respective 
melting  points : 


Number. 

Parts. 

Melts  at 
degrees 

F. 

Number. 

Parts. 

Melts  at 
degrees 
F. 

Tin. 

Lead. 

Tin. 

Lead. 

I . 

1 

25 

558° 

7 . 

I 

334° 

2 . 

1 

IO 

54i 

8 . 

2 

I 

340 

3 . 

1 

5 

51 1 

j  9 . 

3 

I 

356 

A . 

1 

7 

482 

10 . 

4 

I 

7  6  5 

5 . 

1 

2 

441 

II . 

5 

I 

378 

6 . 

1 

I 

370 

12 . 

1 

6 

I 

380 

For  ordinary  plumbers’  work  the  solders  from  4  to  8  are  used 
with  tallow  as  a  flux.  For  lead  and  tin  pipes  No.  8  is  used  with  a 
mixture  of  resin  and  sweet  oil  as  a  flux.  For  Britannia  metal  No. 
8  is  used  with  chloride  of  zinc  or  resin  as  a  flux.  It  can  also  be 
employed  for  soldering  cast-iron  and  steel,  with  common  resin  or 
sal-ammoniac  as  a  flux.  The  same  solder  may  also  be  used  for  cop¬ 
per  and  many  of  its  alloys,  such  as  brass,  gun  metal,  etc.,  sal- 
ammoniac,  chloride  of  zinc  or  resin  serving  as  a  flux.  Solder  No. 
5  is  what  is  called  in  England  plumbers'  sealed  solder,  which  is 
assayed  and  stamped  by  an  officer  of  the  “  Plumbers’  Company.” 


SOLDETirNG  AND  SOLDERS. 


421 


To  prepare  soft  solder  first  melt  the  tin,  best  in  a  porcelain  or 
stone  vessel,  as  with  the  use  of  an  iron  vessel  there  is  danger  of  the 
absorption  of  iron  by  the  solder.  The  tin  being  completely  melted 
add  the  lead  in  small  portions  and  combine  the  two  metals  by 
stirring  with  a  stick  of  wood.  Then  pour  the  finished  alloys  into 
suitable  moulds,  the  best  shaped  being  that  of  thin  bars  about  7 ^ 
by  1^  inches  and  to  inch  thick. 

The  quality  of  a  solder  is  judged  by  the  appearance  of  the  sur¬ 
face  of  the  cast  pieces,  special  value  being  attached  to  its  being 
radiated  crystalline,  which  is  technically  called  the  “flower,”  and 
should  have  a  stronger  lustre  than  the  dull  ground  of  a  dead  silver 
color.  If  the  solder  shows  a  uniform  gray-white  color  it  contains 
too  little  tin,  and  it  is  best  to  remelt  it  with  the  addition  of  a  small 
quantity  of  that  metal. 

Bismuth  Solder. — Bismuth  1  part,  tin  1,  and  lead  1.  It  melts  at 
284°  F.  This  solder  liquefies  very  readily  and  is  considerably  harder 
than  ordinary  soft  solder,  but  much  more  expensive.  Since  every 
readily  fusible  metallic  composition  can  be  used  for  soldering  the 
fusible  alloys  of  cadmium  and  bismuth  (see  p.  82)  might  be  classed 
with  soft  solders.  On  account  of  their  costliness  they  are,  how¬ 
ever,  only  used  in  exceptional  cases. 

Hard  Solders. — Under  this  name  very  different  alloys  are  used, 
their  composition  depending  principally  on  that  of  the  metals  or 
alloys  to  be  soldered.  Though  hard  solders  are  found  in  com¬ 
merce  every  workman  should  learn  to  make  his  own  hard  solder, 
since  in  many  instances  he  can  expect  success,  not  only  by  a 
thorough  knowledge  of  the  properties  of  the  materials  to  be  united, 
but  also  of  the  metal  he  proposes  to  flow  on  them. 

Spelter  Solder. — This  is  used  in  brazing.  It  is  composed  of  equal 
parts  of  copper  and  zinc.  Heat  the  brass  in  a  crucible  to  a  red- 
heat  with  a  flux  of  charcoal  dust  and  borax,  and  then  add  the  zinc. 
If  the  zinc  be  put  in  at  first  it  will  evaporate  or  “  burn  out  ”  before 
the  copper  melts.  If  heated  too  hot  after  melting  the  zinc  will 
evaporate,  passing  into  the  air  and  coating  surrounding  objects  with 
white  feathery  flakes.  If  kept  melted  long  a  little  more  zinc  should 
be  added  if  the  solder  is  to  be  used  on  brass,  but  for  iron  consider- 


422 


TIIE  METAL  WORKER’S  n ANDY-BOOK. 


able  zinc  may  burn  out  before  it  deteriorates.  It  is  cast  in  ingots, 
heated  to  a  red-heat  and  hammered  while  hot.  If  too  hot  it  will 
cake,  but  if  at  just  the  right  temperature,  it  will  granulate  into  fine, 
lustrous  particles,  not  losing  their  metallic  yellow  color. 

The  following  table  shows  the  centesimal  composition  of  various 
kinds  of  hard  solders  which  have  stood  a  practical  test  for  various 
purposes : 


Very  refractory 


Refractory . 

Readily  fusible . 

Half-white,  readily  fusible . 

White . 

Malleable  solder . 

Hard  solder  according  to  Volk. . . . 


Copper. 

Zinc. 

Tin. 

57-94 

42.06 

58-33 

41.67 

50.00 

5000 

33-34 

66.66 

44-00 

49.90 

3-30 

57-44 

27.98 

14.58 

72.00 

18.00 

4.00 

53-30 

46.70 

Lead. 


These  solders  being  generally  prepared  by  melting  together  brass 
and  zinc,  the  proportions  required  for  the  purpose  are  given  in  the 
following  table : 


Tarts. 

Brass. 

Zinc. 

Tin. 

85.42 

7.00 

3.00 

4.00 

5.00 

5.00 

12.00 

12.58 

I.  OO 

«  it 

Refractory . 

I. OO 

«< 

I. OO 

Readily  fusible . 

2. CO 

4.OO 

5.00 

20.00 

Half-white . 

1. 00 

it 

44-00 

40.00 

22.00 

2.00 

White . 

2.00 

8.00 

2.00 

4.00 

30.00 

It 

18.00 

12  OO 

Very  ductile . 

78.25 

81.12 

17.25 

18.88 

SOLDERING  AND  SOLDERS. 


423 


Solders  for  Aluminium. — French  manufacturers  use  five  kinds  of 
solder  in  soldering  aluminium  ;  their  composition  is  as  follows : 


The  solders  are  made  by  first  preparing  an  aluminium  copper 
alloy  and  mixing  this  with  the  required  quantity  of  zinc.  The 
copper  is  first  melted  and  the  aluminium,  divided  into  three  or  four 
portions,  is  gradually  introduced  into  the  melted  copper,  a  perfect 
mixture  being  effected  by  stirring.  When  the  last  portion  of 
aluminium  has  been  added  throw  in  the  zinc,  and  at  the  same  time 
some  fat  or  resin,  then  stir  quickly  and  briskly,  immediately  remove 
the  crucible  from  the  fire  and  pour  the  alloy  into  iron  moulds 
previously  rubbed  with  coal  tar  oil  or  benzine. 

For  soldering  aluminium  with  the  blow-pipe  the  following  com¬ 
position  is  recommended  :  Silver,  io  parts;  copper,  io;  aluminium, 
20 ;  tin,  60 ;  zinc,  30. 

For  soldering  with  the  common  soldering  iron  use :  Tin,  95  parts, 
and  bismuth,  5  ;  or  tin,  97  parts,  and  bismuth,  3.  The  flux  to  be 
used  in  all  cases  is  either  paraffine,  stearin  or  vaseline.  The  articles 
must  be  well  cleaned  before  soldering  and  heated  just  enough  to 
make  the  solder  adhere. 

Soldering  of  Aluminium  Bronze. — To  solder  aluminium  bronze 
with  ordinary  soft  (pewter)  solder :  Cleanse  well  the  parts  to  be 
joined  from  dirt  and  grease.  Then  place  the  parts  to  be  soldered 
in  a  strong  solution  of  sulphate  of  copper  and  place  in  the  bath  a 
rod  of  soft  iron  touching  the  parts  to  be  joined.  After  a  while  a 
copper-like  surface  will  be  seen  on  the  metal.  Remove  from  bath, 
rinse  quite  clean  and  brighten  the  surfaces.  These  surfaces  can 


424 


THE  METAL  WORKER’S  HANDY-BOOK. 


then  be  tinned  by  using  a  fluid  consisting  of  zinc  dissolved  in 
hydrochloric  acid  in  the  ordinary  way  with  common  soft  solder. 

Hu  lot' s  Solder  for  Aluminium  Bronze. — Lead-tin  solder  (equal 
parts  of  lead  and  tin)  with  12.5,  25,  or  50  per  cent,  of  zinc 
amalgam. 

Solders  for  Aluminium  Bronze  Jewelry.  I.  Hard  Solder  for  10 
per  cent.  Brorize. — Gold,  88.88  per  cent.;  silver,  4.68;  copper, 
6.44. 

II.  Middling  Hard  Solder  for  10  per  cent.  Bronze. — Gold,  50.40 
percent.;  silver,  27.60;  copper,  18. 

Soft  Solder  for  Aluminium  Bronze. — Brass  (copper,  70  per 
cent.;  tin,  30),  14.30  per  cent.;  gold,  14.30;  silver,  57.10; 
copper,  14.30. 

Argentan  Solders. — These  solders  being  not  only  used  for  solder¬ 
ing  German  silver,  but  also  for  steel  articles,  efforts  have  been  made 
to  prepare  compositions  answering  all  demands,  of  which  the  fol¬ 
lowing  have  stood  a  practical  test : 

I.  Readily  Fusible  Argentan  Solder. — Copper,  35  parts  ;  zinc, 
57  ;  nickel,  8. 

II.  Less  Fusible  Argentan  Solder  (especially  adapted  for  iron  and 
steel).  Copper,  38  parts;  zinc,  50;  nickel,  12. 

Soldering  Cast-iron. — In  a  foundry  doing  agricultural  work  there 
are  a  great  many  alterations  to  be  made  to  patterns,  and  often  it  is 
desirable  to  solder  brass  to  cast-iron  where  drilling  and  rivetting  to 
the  pattern  would  make  anything  but  a  neat  job.  By  a  great  many 
men  who  work  on  iron  patterns  it  is  considered  quite  a  secret  to 
solder  on  cast-iron,  but  it  is  not  so.  The  process  is  very  much  the 
same  as  in  soldering  on  a  tinned  surface.  If  the  part  of  iron  to  be 
soldered  is  cast-iron  that  is  hard  and  thin,  it  should  be  polished  on 
an  emery  wheel  and  made  clean  and  bright.  Then  dip  it  in  potash 
water,  after  which  dip  it  for  an  instant  in  clean  water  and  wash  it 
quickly  with  undiluted  hydrochloric  acid  of  the  ordinary  strength ; 
go  over  it  with  powdered  resin  and  solder  made  from  half  tin  and 
half  lead.  This  must  be  done  quickly  before  the  surface  has  time 
to  dry. 

Another  Plan  is  this :  File  the  surface  clean  and  wash  as  before, 


SOLDERING  AND  SOLDERS. 


425 


wipe  it  over  with  a  flux  made  of  sheet  zinc  dissolved  in  hydrocnloric 
acid  until  it  is  surcharged,  or  is  a  saturated  solution  and  has  been 
diluted  with  its  own  quantity  of  water;  then  sprinkle  powdered 
sal-ammoniac  on  it  and  heat  it  on  a  charcoal  fire  until  the  sal- 
ammoniac  smokes.  Dip  it  in  melted  tin,  and  then  remove  and  rap 
off  the  surplus  tin. 

To  Solder  Cast-iron  Objects. — Broken  decorated  cast-iron  objects 
may  be  soldered  by  first  removing  the  dirt  from  the  surfaces  to  be 
joined  and  then  brushing  the  latter  with  a  scratch-brush  until  they 
are,  so  to  say,  covered  with  a  dry  coat  of  brass.  The  surfaces  thus 
covered  with  brass  are  then  tinned  in  the  same  manner  as  brass,  and 
the  parts  soldered  together  in  the  usual  way. 

Soldering  with  Dry  Lead  Chloride. — The  process  consists  in 
bringing  the  soldering  plane  of  the  heated  soldering-iron  in  contact 
with  the  dry  lead  chloride.  When  the  lead  chloride  is  melted  the 
solder  is  taken  up  in  the  usual  manner  and  applied  to  the  joints 
to  be  united.  In  this  manner  lead,  zinc,  copper,  brass  or  iron  can 
be  readily  soldered  with  lead  with  or  without  the  use  of  soldering 
liquid.  This  interposing  role  of  lead  chloride  for  soldering  pur¬ 
poses  is  also  valuable  for  metallic  coatings  in  a  dry  way  by  melting 
one  metal  upon  the  other.  The  articles  to  be  coated  are  brought 
successively  or  simultaneously  in  contact  with  the  melted  lead 
chloride  and  the  metal  which  is  to  furnish  the  coating.  According 
to  the  shape  of  the  article  to  be  coated  the  melting  may  be  effected 
either  upon  the  article  itself  or  the  coating  accomplished  by  dip¬ 
ping  the  object  into  the  melted  substances.  Copper,  brass  and 
iron  can  in  this  manner  be  coated  with  zinc,  tin  or  lead. 

Gold  Solders. — In  color  and  fusibility  the  solders  used  for  articles 
of  gold  should  approach  as  nearly  as  possible  the  alloy  of  which 
the  latter  are  made ;  the  smaller  the  content  of  gold  in  the  alloy 
to  be  soldered  the  more  fusible  the  solder  must  be.  The  following 
table  gives  the  composition  of  some  gold  solders  in  general  use : 


426 


THE  METAL  WORKER'S  HANDY-ROOK. 


Parts. 

Gold. 

Silver. 

Copper. 

Zinc. 

Hard  solder  for  fineness  750 . 

Soft  “  “  750 . 

Solder  “  583 . 

“  “  583 . 

“  for  less  fineness  than  583 _  ... 

“  “  “  “583 . 

“  “  “  “  583 . 

“  readily  fusible . 

“  “  “  for  yellow  gold . 

q  q  q  0  q  q  q  q\o 

ChNf^NWHWHC) 

2.0 

7.0 

2.0 

O.5 

2.0 

2.0 

54-74 

5-o 

1.0 

30 

1 .0 

o-5 

1.0 

2.0 

28.17 

q  q 

LO  P-! 

Solder  for  Enamelled  Work. — Articles  which  after  being  finished 
are  to  be  decorated  with  enamel  cannot  be  soldered  with  every  kind 
of  gold  solder,  since  many  enamels  require  so  high  a  degree  of  heat 
for  fusion  as  to  endanger  the  durability  of  the  soldered  joints. 
Hence,  solders  with  a  high  melting  point  have  to  be  used.  The 
following  compositions  will  be  found  to  answer  all  requirements  : 

I.  Refractory  Solder. — Gold,  74  parts;  silver,  18. 

II.  More  Readily  Fusible  Solder. — Gold  (750  fineness),  32  parts ; 
silver,  9  ;  copper,  3. 

To  Remove  Tarnish  froni  Gold  After  Hard  Soldering. — First  pro¬ 
tect  the  gold  by  painting  it  over  with  yellow  ochre  ground  up  with 
water  and  a  very  little  borax.  After  soldering  throw  it  into  a 
pickle  composed  of  water  6  parts  and  sulphuric  acid  1  part.  A 
copper  boiling  dish  may  be  used  for  this  pickle.  If  the  article  on 
coming  out  of  this  pickle  is  whitish  looking  and  shows  too  much 
of  the  silver  alloy,  dip  it  for  a  moment  in  a  hot  mixture  of  sulphuric 
acid  and  saltpetre  (no  water).  Wash  and  polish  with  rotten  stone 
and  oil ;  then  wash  again  and  polish  with  rouge. 

Silver  Solders. — The  composition  of  these  solders  varies  accord¬ 
ing  to  the  purpose  for  which  they  are  to  be  used.  In  the  following, 
the  compounds  employed  in  the  preparation  of  the  solders  most 
frequently  used,  are  given. 


SOLDERING  AND  SOLDERS. 


427 


Hard  Silver  Solders  are  used  for  soldering  silver  ware  and  fine 
articles  of  brass,  copper,  steel  and  iron.  I.  Hard  Silver  Solder  for 
the  First  Soldering  is  generally  composed  of : 


I. 

II. 

hi. 

IV. 

V. 

VI. 

VII. 

VIII. 

IX. 

X. 

XI. 

Parts. 

Fine  silver. . 
Copper . 

4 

2 

19 

■? 

57 

28.6 

66.7 1 66.3 

27.7  2Z.7 

50 

33-4 

II 

4 

1 

16 

15 

I 

6 

76 

18 

9 

157 

35 

3 

I 

Zinc . 

.... 

143 

10 

II 

16.6 

II.  Softer  Hard  Silver  Solder  for  After  Soldering,  i.  e. ,  for  solder¬ 
ing  articles  having  parts  already  soldered  and  requiring  therefore  a 
more  fusible  solder : 


I. 

II. 

III. 

IV. 

V. 

VI. 

VII. 

VIII. 

IX. 

Parts. 

Medium  fine  silver . 

7 

l6 

l6 

3-5 

2 

10.5 

68.8 

67,1 

48-3 

Zinc . 

I 

I 

I 

I 

I 

3 

8.2 

io-5 

l6.I 

Copper . . . 

2.6 

3 

4-5 

2-3 

24.4 

32-3 

Tin . 

3-3 

Alloy  for  Cold  Soldering. — An  alloy  which  is  useful  when  metals 
are  required  to  be  soldered  together  at  a  low  temperature  is  pre¬ 
pared  as  follows  :  Finely  divided  copper  is  obtained  by  adding  zinc 
to  a  solution  of  sulphate  of  copper.  From  20  to  30  parts  of  this 
copper,  according  to  the  hardness  required,  are  mixed  in  a  cast- 
iron  or  porcelain  mortar  with  concentrated  sulphuric  acid,  to 
which  are  finally  added  70  parts  of  mercury.  The  amalgam  thus 
formed  is  thoroughly  washed  with  water  in  order  to  remove  the 
sulphuric  acid,  and  after  being  left  untouched  for  some  time  it 


428 


THE  METAL  WORKER’S  RANDY-BOOK. 


becomes  sufficiently  hard  to  scratch  lead.  In  using  the  alloy  for 
soldering  it  is  warmed  until  it  assumes  the  consistency  of  wax,  in 
which  state  it  can  be  applied  to  the  joint. 

Copper  is  the  best  material  for  joining  iron  to  iron,  whether 
wrought  or  cast.  It  unites  the  two  surfaces  very  firmly,  and,  by 
reason  of  its  ductility  and  toughness,  allows  of  the  soldered  articles 
being  bent  into  almost  any  shape.  To  solder  iron  or  steel  place  a 
thin  strip  of  copper  along  the  junction,  bind  the  plates  together 
with  wire  and  cover  them  an  inch  deep  with  clay  free  from  sand. 
For  soldering  iron  to  iron  bring  the  plates,  when  dry,  to  a  white 
heat  and  then  plunge  them  into  cold  water ;  for  iron  to  steel  or  steel 
to  steel,  cool  slowly  from  the  white  heat.  The  vitrified  clay  is  then 
broken  off. 

To  Solder  Copper  Wire. — In  soldering  copper  wire  for  electrical 
work,  acid  is  often  used,  and  the  resulting  “greenness”  is  a  sure 
indication  of  corrosion,  which  may  extend  under  the  solder, 
covering  the  copper  and  forming  serious  resistance  against  the  pas¬ 
sage  of  the  current.  Indeed,  it  is  presumable  that  the  resistance  of 
both  light  and  power  as  well  as  of  signal  circuits  are  often  increased 
by  such  corrosion  from  the  use  of  acid  in  soldering.  Sal-ammoniac 
seems  to  be  the  natural  flux  with  copper,  but  corrosion  frequently 
takes  place  where  this  salt  is  used  as  a  flux.  The  only  flux  per¬ 
missible  in  electric  soldering  in  copper  and  brass  is  resin.  Clean 
copper  will  flux  completely  with  resin  provided  the  surfaces  are 
clean  when  the  resin  is  applied.  A  bottle  of  strong  soda  water, 
fitted  with  a  sponge  cover,  can  be  carried  with  any  soldering  kit. 
The  soda  quickly  removes  any  grease  or  dirt,  is  “  killed  ”  by  con¬ 
tact  with  resin,  and  forms  a  perfect  cleaning  agent  for  preparing 
copper  or  brass  for  soldering  with  resin  as  a  flux. 

To  Solder  Saws. — A  piece  of  charcoal,  a  blow-pipe,  some  spelter 
and  borax  are  required.  File  the  ends  of  the  saw  smooth,  so  that 
one  side  laps  over  the  other,  fit  the  teeth  opposite  each  other  and 
bind  it  with  iron  wire  to  keep  in  place.  Then  moisten  the  lap 
with  borax  dissolved  in  water  and  place  the  saw  on  the  charcoal. 
Place  the  broken  parts  near  a  gas  jet,  sprinkle  the  parts  previously 
wetted  with  the  spelter  and  blow  the  flame  of  gas  until  the  spelter 


SOLDERING  AND  SOLDERS. 


429 


runs ;  let  it  get  cool  before  removal.  When  quite  cold  file  it  flat 
with  the  other  part  of  the  saw. 

To  Solder  Without  a  Soldering  Iron. — Pieces  of  brass  can  be 
soldered  without  it  being  possible  to  detect  the  joint  by  filing  the 
pieces  so  as  to  fit  exactly,  moistening  them  with  a  soldering  liquid, 
then  placing  a  piece  of  smooth  tin-foil  between  them,  tying  them 
together  with  wire  and  heating  over  a  lamp  or  fire  until  the  tin- 
foil  melts.  With  good  soft  solder  almost  all  soldering  can  be  done 
over  a  lamp  without  the  use  of  a  soldering  iron.  The  different 
degrees  of  fusibility  of  solders  can  also  be  advantageously  used  for 
several  solderings  and  joints  on  the  same  piece.  By  soldering 
first  with  a  fine  solder  composed  of  lead,  2  parts;  tin,  x  ;  and 
bismuth,  2,  there  will  be  no  danger  of  melting  when  close  to  the 
jointed  part ;  another  piece  is  soldered  on  with  solder  composed 
of  lead,  4  parts;  tin,  4;  and  bismuth,  1.  The  best  soldering  liquid 
to  be  used  is  composed  of  equal  parts  of  water  and  hydrochloric 
acid  saturated  with  zinc. 

To  Color  Soft  Solder. — For  giving  the  solder  used  in  soldering 
copper  the  same  color  as  the  latter,  prepare  first  a  saturated  solu¬ 
tion  of  pure  sulphate  of  copper  and  apply  it  to  the  solder.  By 
then  touching  the  solder  with  an  iron  or  steel  wire  it  becomes 
covered  with  a  film  of  copper  which  may  be  augmented  as  much 
as  desired  by  repeated  moistening  with  the  solution  of  copper  and 
touching  with  the  wire.  If  the  soldering  is  to  show  a  yellow  color 
mix  1  part  of  saturated  solution  of  sulphate  of  zinc  with  2  parts 
of  solution  of  sulphate  of  copper,  apply  the  mixture  to  the  coppered 
place  and  rub  the  latter  with  a  zinc  rod.  If  the  soldered  place  is 
to  be  gilded,  copper  it  as  above  described,  then  coat  with  solution 
of  gum  or  isinglass  and  scatter  bronze  powder  upon  it.  This 
forms  a  surface  which,  when  the  gum  is  dry,  can  be  polished. 

To  Make  Platinum  Adhere  to  Gold. — Platinum  can  be  made  to 
:  adhere  to  gold  by  soldering  in  the  following  manner  :  A  small 
quantity  of  fine,  or  18-carat,  gold  should  be  sweated  into  the  sur¬ 
face  of  the  platinum  at  nearly  a  white  heat,  so  that  the  gold  will 
soak  into  the  face  of  the  platinum.  Ordinary  solder  will  then 
adhere  firmly  to  the  face  obtained  in  this  manner. 


430 


THE  METAL  WORKER’S  HANDY-BOOK. 


Autogenous  Soldering  takes  place  by  the  fusion  of  the  two  edges 
of  metals  themselves  without  interposing  another  metallic  alloy  as 
a  bond  of  union.  This  is  accomplished  by  directing  a  jet  of 
burning  hydro-gas  from  a  small  movable  beak  upon  the  two  sur¬ 
faces  or  edges  to  be  soldered  together.  Metals  thus  joined  together 
are  much  less  apt  to  crack  asunder  at  the  line  of  union  by  differ¬ 
ence  of  temperature,  flexibility,  etc.,  than  when  the  common 
soldering  process  is  employed.  This  method  of  soldering  is 
especially  of  great  advantage  in  chemical  works  for  joining  the 
edges  of  sheet-lead  for  sulphuric  acid  chambers  and  concentration 
pans,  because  any  solder  containing  tin  would  soon  corrode. 


XV. 

WELDING  AND  WELDING  COMPOUNDS. 

In  order  to  find  a  true  analogy  to  welding  we  need  go  no  further 
than  the  ordinary  “sticking  together'’  of  two  pieces  of  cobblers’ 
wax,  pitch,  putty  or  clay.  These  are  in  a  viscous  or  semi-fluid 
condition,  and  they  cohere  by  an  action  similar  to  the  transfusion 
or  intermingling  and  uniting  of  two  liquids.  Iron  and  platinum 
pass  through  a  viscous  or  pasty  stage  on  their  way  from  the  solid 
to  the  liquid  state,  and  the  temperature  at  which  this  pasty  con¬ 
dition  occurs  is  the  welding  heat.  The  chief  practical  difficulty  in 
welding  iron  arises  from  the  fact  that  at  a  welding  heat  it  is  liable 
to  oxidation,  and  the  oxide  of  iron  is  not  viscous  like  the  metallic 
iron.  The  union  of  different  pieces  of  iron  and  steel  by  welding 
succeeds  well  only  when  the  surfaces  of  contact  are  as  large  as 
possible,  free  from  oxide  and  scale,  and  sufficiently  heated.  To 
enlarge  the  surfaces  of  contact  of  two  bars  to  be  welded  together 
the  ends  are  upset  and  sloped,  or  the  end  of  one  bar  is  ripped 
open  and  the  end  of  the  other  bar  pointed  like  a  wedge  and  in¬ 
serted  in  the  slit.  Iron  has  to  be  heated  to  a  white  heat,  whilst 
cast-steel  welds  at  a  bright  red  heat;  by  heating  the  latter  too 
much  it  loses  in  quality — it  burns. 


WELDING  AND  WELDING  COMPOUNDS. 


431 


To  obtain  a  clean  surface  on  the  pieces  to  be  united  care  must 
be  had  to  remove  the  scale  formed  in  heating.  This  is  effected  by 
scattering  upon  them  so-called  “welding  powders,”  with  which 
the  scale  forms  a  readily  fusible  slag  ;  silicic  acid  (sand)  and  boric 
acid  are  most  frequently  used.  In  welding  steel  other  substances 
are  added  to  augment  the  fluidity  of  the  slag. 

Cast-iron  or  steel  containing  more  than  2  per  cent,  of  carbon 
cannot  be  welded,  because  the  compound  of  iron  with  so  much 
carbon  is  more  fusible  than  pure  iron,  or  than  steel  with  less  car¬ 
bon,  and  it  runs  more  suddenly  or  directly  from  the  solid  state 
into  that  of  a  liquid,  and  hence  presents  no  workable  range  of 
weldable  viscosity. 

There  is  one  point  in  welding  steel  which  cannot  be  too  strongly 
insisted  upon,  and  that  is  that  the  pieces,  after  having  been  brought 
to  the  welding  point,  should  not  be  struck  heavily  with  the  hammer, 
but  only  tapped  lightly  at  first  until  they  have  begun  to  weld  ;  after 
that  the  sledge  or  steam-hammer  may  be  used  with  perfect  freedom. 
Another  important  thing  in  welding  steel  is  the  heat.  While  it  is 
impossible  to  give  any  specific  rules  on  this  point,  the  general  rule, 
which  will  be  found  to  hold  good  in  all  cases,  is  not  to  heat  the 
steel  any  higher  than  is  absolutely  necessary  to  effect  a  weld — 
the  higher  the  steel  is  in  carbon  the  lower  the  heat  at  which  it 
ought  to  be  worked,  hence  necessitating  heavier  hammers — and 
next,  not  to  finish  the  operation  at  too  low  a  temperature.  It  will 
be  best  to  work  the  steel  as  rapidily  as  possible,  reheat  as  often  as  re¬ 
quired  to  prevent  working  or  finishing  cold,  and  anneal  immediately 
after  welding  the  whole  piece — not  only  the  immediate  vicinity  of 
the  weld — containing  the  weld.  The  annealing  heat  should  always 
be  higher  than  that  at  which  the  piece  was  finished.  Another 
source  of  danger  to  the  homogeneity  of  the  finished  product  is  to 
be  found  in  cold-straightening.  The  presses  in  many  mills  are  so 
constructed  as  to  exert  absolute  shearing  stresses,  and  are  apt  to  do 
more  harm  than  any  subsequent  service  can  do.  Cold-straighten¬ 
ing  ought  to  be  done  at  black  heat,  and  the  local  effects  of  the 
press  be  modified  by  distribution  over  a  large  area.  This  can  be 
accomplished  by  the  use  of  broad  oak  wedges  or  the  insertion  of 


432 


THE  METAL  WORKER’S  HANDY-BOOK. 


pieces  of  plank.  Generally,  plates,  angles,  beams,  etc.,  have  of 
necessity  to  undergo  more  or  less  hammering  in  the  course  of  con¬ 
struction,  and  as  this  produces  effects  comparable  to  punching  and 
shearing,  though  in  a  much  less  degree,  it  becomes  necessary,  in 
steel  construction,  to  modify  these  effects  in  the  same  way,  by 
protecting  the  metal  surface  with  wood  and  substituting  heavy 
wooden  mallets  for  sledges.  In  fine,  the  working  of  steel  in  every 
stage  requires  care — and,  above  all,  intelligence — and  the  men 
engaged  in  it  must  be  impressed  with  the  necessity  for  careful 
manipulation  and  rational  treatment.  Undoubtedly  the  steel  must 
in  the  first  place  possess  the  proper  qualities  for  structural  purposes, 
but  then  it  must  also  be,  subsequently,  properly  treated  if  it  is  to 
bring  those  qualities  into  the  finished  structure. 

To  Weld  Cast-steel. — I.  The  following  precautions  are  necessary 
to  ensure  success :  Keep  the  cast-steel  from  the  air  while  being 
heated;  heat  as  quickly  as  possible;  don’t  make  it  too  hot  or  it 
will  burn,  and  break  in  pieces  when  hammered — for  cast-steel  re¬ 
quires  a  low  welding  heat ;  strike  lightly  at  first,  and  increase  to 
heavy  blows;  don’t  use  coals,  because  they  contain  sulphur,  and 
will  give  the  surface  of  the  steel  a  coating  of  sulphide  of  iron  ;  but 
use  coke,  or  what  the  smiths  term  “  breeze,”  that  is,  coal  well  burnt 
and  the  cinders  washed.  Use  the  following  flux:  Borax,  %  lb.  ; 
washing  potash,  ^  lb.  ;  and  a  small  quantity  of  white  glass  pow¬ 
dered ;  melt  together,  and  when  cold  pound  it.  This  flux  will 
dissolve  the  oxide  that  forms.  Apply  some  before  putting  into  the 
fire  to  protect  the  surface  of  the  work  from  oxide,  and  apply  more 
at  your  own  discretion.  If  wanted  to  weld  cast-steel  to  iron,  the 
iron  will  require  a  greater  heat  than  steel. 

II.  Mix  boric  acid,  41.5  parts;  common  salt,  35  ;  ferrocyanide 
of  potash,  15.5  to  26.7;  resin,  7.6;  carbonate  of  soda,  3  to  5. 

This  mixture  does  excellent  service.  It  has,  however,  the  dis¬ 
advantage  of  not  remaining  unaltered  if  kept  for  any  length  of 
time,  as  it  gradually  decomposes  and  assumes  a  blue  color.  But 
this  is  a  minor  evil,  as  the  compound  is  so  easily  prepared. 

III.  Fiala  of  Prague  uses  pulverized  white  marble  for  welding 
cast-steel.  The  two  pieces  to  be  welded  together  are  heated,  and, 


WELDING  AND  WELDING  COMPOUNDS. 


433 


after  rolling  in  marble-dust,  are  promptly  joined  together  and 
subjected  to  a  good  hammering. 

American  Welding  Compound for  Welding  Steel  to  Steel.- — Flowers 
of  sulphur,  i  part;  sal-ammoniac,  2;  borax,  10. 

Another  Formula  is  as  follows:  Boric  acid,  41.5  ;  common  salt, 
35  ;  prussiate  of  potash,  15.5  ;  calcined  soda,  8. 

Welding  Compound  to  Weld  Steel  to  Wrought-iron  at  a  Red-heat. 
— I.  Pulverize  and  mix  with  water  6  parts  by  weight  of  borax,  2  of 
sal-ammoniac,  1  of  prussiate  of  potash,  and  y2  of  resin.  Boil  the 
mixture,  stirring  it  constantly,  until  it  forms  a  stiff  paste,  which  is 
allowed  to  harden  over  the  fire.  When  cold  pulverize  and  mix  it 
with  1  part  of  wrought-iron  filings  free  from  rust.  In  using  it 
scatter  the  powder  upon  the  red-hot  pieces  and  liquefy  it  over  the 
fire. 

II.  Boric  acid,  35  parts;  common  salt,  30.1;  prussiate  of 
potash,  26.7;  colophony,  7.6. 

To  Weld  Steel  to  Iron  or  Steel.- — Mr.  Paul  Herzog  gives  the  fol¬ 
lowing  as  a  special  composition  discovered  by  him  for  use  in  weld¬ 
ing  steel  to  steel  or  to  iron :  Borax,  500  parts  by  weight ;  sal- 
ammoniac,  70;  prussiate  of  potash,  70;  unrusted  iron  filings,  35. 
This  compound  is  to  be  pulverized  in  a  mortar,  and  then  turned 
into  a  sheet-iron  pot  or  crucible;  water  is  added  until  a  thick 
paste  results,  and  then  the  crucible  is  put  over  a  wood-fire  and  the 
contents  constantly  stirred.  The  resulting  mass  resembles  pumice 
stone  with  green  and  gray  streaks ;  this  is  cooled,  pulverized,  and 
is  at  once  ready  for  use. 

Welding  Compound  for  Welding  Wrought-iron  to  Wrought-iron  at 
a  Red-heat. — Borax,  1  part  by  weight ;  sal-ammoniac,  ]/2  ;  and 
water,  y2.  Boil  these  ingredients,  with  constant  stirring,  until  the 
mixture  is  stiff,  and  then  allow  it  to  harden  over  the  fire.  When 
cool  the  compound  is  pulverized  and  intimately  mixed  with  y 
part  of  wrought-iron  filings  free  from  rust.  The  pieces  to  be  welded 
are  first  dove-tailed  or  tied  together,  and  the  place  to  be  welded  is 
made  red-hot ;  the  powder  is  then  scattered  upon  it  and  liquefied 
over  the  fire.  A  few  light  taps  with  the  hammer  suffice  to  join 
the  two  pieces  together. 

28 


434 


THE  METAL  WORKER’S  HANDY-BOOK. 


To  Thoroughly  and  Firmly  Unite ,  by  Welding,  Steel  with  Steel, 
Cast-steel  with  Cast-steel  and  Cast-steel  with  Iron.— To  weld  steel 
of  larger  and  smaller  dimensions,  for  instance,  piston-rods  or 
spindles  of  spinning  frames,  cut  off  the  bad  end,  upset  it  and  cut 
it  open  with  a  chisel ;  then  in  the  same  manner  prepare  the  piece 
to  be  welded  on  and  join  both  parts.  The  part  of  the  spindle  to 
be  welded  is  then  heated  to  a  slight  white-heat  in  a  charcoal  fire, 
and  some  powder  of  the  mixture  given  below  scattered  upon  it  by 
means  of  an  iron  spoon.  When  the  powder  is  melted  another 
portion  is  added  and  the  welding  joint  closed  by  light  blows  with 
the  hammer. 

To  prepare  the  powder,  pulverize  in  a  covered  mortar,  500  parts 
by  weight  of  borax,  70  of  sal-ammoniac,  70  of  yellow  prussiate  of 
potash  and  35  of  iron  filings  free  from  rust,  and  bring  all  into  a 
sheet-iron  crucible.  Then  add  sufficient  water  to  form  a- thick 
paste,  and  boil,  with  constant  stirring,  over  a  moderate  wood-fire. 
When  correctly  manipulated  a  green  and  gray  mass  resembling 
pumice  stone  is  formed,  which,  when  cold,  is  pulverized  and  then 
ready  for  use.  By  the  use  of  this  powder  many  spindles  and  piston- 
rods  up  to  a  diameter  of  2^/2  inches  have  been  successfully  welded. 
The  powder  may  also  be  used  for  welding  pieces  of  cast-steel  as 
well  as  for  joining  cast-steel  and  iron. 

Improved  Method  of  Welding. — It  is  well  known  that  in  order  to 
weld  iron  in  a  durable  manner  its  surface  must  be  free  from  oxide, 
which  formerly  could  only  be  effected  with  a  welding  heat  of 
2,800°  F.  Such  a  high  temperature  is,  however,  injurious  to 
the  quality  of  the  iron,  and  still  more  so  to  that  of  steel,  so 
that  many  varieties  of  the  latter  could  not  be  welded  in  this 
•manner. 

To  overcome  this  difficulty  pulverized  borax  is  used,  which, 
however,  cannot  be  uniformly  distributed  over  the  surface  of  the 
iron.  Lafitte  now  uses  a  gauze  of  very  flexible  wire,  and  applies 
the  fluxing  agent  uniformly  to  both  sides  of  the  gauze,  or  also  to 
paper.  For  small  surfaces  it  frequently  suffices  to  form  a  leaf  from 
the  agglomerated  fluxing  agent  and  filings.  Instead  of  covering 
the  two  surfaces  with  powder,  the  wire  gauze,  which  consists  of  the 


WELDING  AND  WELDING  COMPOUNDS. 


435 


same  material  as  the  substances  to  be  welded,  is  placed  between 
them  and  welded  in.  The  welding  takes  place  at  a  much  lower 
temperature  and  the  fluxing  agent  generally  volatilizes  while  the 
wire  gauze  melts  and  unites  with  the  surface. 

To  Weld  Copper. — A  mixture  composed  of  i  part  soda  phos¬ 
phate  and  2  boric  acid  is  used.  The  powder  is  applied  when  the 
metal  is  at  a  dull  red  heat ;  it  is  then  brought  to  a  cherry-red  and 
at  once  hammered.  The  greatest  care  must  be  taken  that  no  char¬ 
coal  or  other  solid  carbon  comes  in  contact  with  the  points  to  be 
welded,  as  otherwise  copper  phosphide  would  be  formed,  which 
would  cover  the  surface  of  the  copper  and  effectually  prevent  a 
weld.  In  this  case  it  is  only  by  careful  treatment  in  an  oxidizing 
fire  and  plentiful  application  of  the  welding  powder  that  the  cop¬ 
per  can  again  be  welded.  It  is,  therefore,  advisable  to  heat  the 
copper  in  a  flame,  for  instance  a  gas  flame.  As  copper  is  a  much 
softer  metal  than  iron,  it  is  much  softer  at  the  required  heat  than 
the  latter  at  its  welding  heat,  and  the  parts  welded  cannot  offer 
any  great  resistance  to  the  blows  of  the  hammer.  They  must, 
therefore,  be  so  shaped  as  to  be  enabled  to  resist  such  blows,  as  well 
as  may  be,  and  it  is  also  well  to  use  a  wooden  hammer,  which,  on 
account  of  its  lightness,  does  not  exert  so  great  a  force. 

Another  Process  is  as  follows :  The  two  pieces  of  copper  to  be 
united  having  been  previously  shaped  so  that  the  surfaces  form  a 
lap  or  other  suitable  joint,  borax  is  applied  on  and  between  the 
surfaces  of  the  joint,  which  are  then  heated  and  hammered.  The 
borax  is  prepared  by  being  heated  until  all  the  water  of  crystalli¬ 
zation  has  evaporated,  when  the  residue  is  pulverized  for  use. 
After  being  hammered  while  hot,  the  joint  is  further  'heated  to  a 
white  heat  and  sprinkled  over  with  common  salt  or  other  equiva¬ 
lent  compound  suitable  for  the  exclusion  of  oxygen,  and  then 
welded ;  or  during  the  welding  operation  a  current  of  chlorine 
gas  may  be  directed  upon  the  heated  copper  joint. 

To  Make  Old  Steel  Rails  New. — Mr.  W.  B.  Middleton,  of  Lan¬ 
caster,  Pa.,  has  discovered  a  method  of  welding  steel  which  prom¬ 
ises  to  confer  very  great  benefit  upon  those  engaged  in  steel  work¬ 
ing.  According  to  the  specification  of  the  invention,  which  has 


436 


THE  METAL  WORKER’S  HANDY-BOOK. 


been  patented  in  the  United  States  and  leading  foreign  countries, 
pieces  of  steel  may,  at  a  proper  welding  heat,  be  perfectly,  cheaply 
and  easily  welded  together  after  the  pieces  to  be  welded  have  been 
coated  with  a  solution  of  silicate  of  soda  or  other  solution  in  which 
silica  is  contained.  In  the  practice  of  the  invention  the  most 
satisfactory  results  have  been  obtained  by  applying  a  solution  of 
silicate  of  soda  to  the  pieces  of  steel  to  be  welded,  by  dipping  the 
pieces  in  the  solution,  or  by  pouring  it  upon  them,  bunching  to¬ 
gether  the  pieces  to  be  welded  and  heating  them  to  an  ordinary 
welding  heat  and  then  passing  them  through  rolls.  This  is  the 
process  followed  with  large  pieces,  but  smaller  articles  can  be 
welded  under  the  hammer  when  previously  treated  with  the  solu¬ 
tion.  The  inventor  finds  that  the  process  is  applicable  for  re¬ 
working  old  steel  rails  and  other  heavy  pieces,  and  it  renders  cer¬ 
tain  kinds  of  steel  scrap,  which  were  formerly  almost  worthless, 
highly  valuable. 

Welding  of  Platinum. — Platinum  does  not  oxidize  when  in  a 
red  hot  state  and  may  be  welded  without  the  use  of  welding  pow¬ 
der  by  simply  placing  the  red-hot  pieces  upon  each  other  and  uniting 
them  by  blows  of  the  hammer.  Nevertheless  the  welding  together 
of  two  pieces  of  platinum  is  a  difficult  operation,  since  platinum 
possesses  the  property  of  yielding  up  the  absorbed  heat  with  great 
rapidity  and  cooling  off  to  such  an  extent  that  the  two  pieces  are 
no  longer  soft  enough  to  be  united.  This  cooling  off  takes  place 
with  such  rapidity  that  the  joining  of  the  hot  pieces  must  be  has¬ 
tened  as  much  as  possible,  it  being  advisable  to  allow  the  flame  of 
the  hydrogen-gas  blow-pipe  to  act  upon  the  pieces  of  platinum 
during  the  entire  operation  of  welding. 

Electric  Welding. — This  process,  the  invention  of  Prof.  Elihu 
Thomson,  is  a  new  art ;  for,  unlike  the  smith,  who  is  confined  to 
iron,  steel  and  platinum,  it  can  weld  any  two  pieces  of  the  same 
metal  or  alloy,  ranging  from  the  most  refractory  metals  to  the 
alloy  which  fuses  at  162°  F.  It  will  join  dissimilar  metals  when 
the  welding  point  of  one  is  not  too  far  in  excess  of  the  fusion  point 
of  the  other. 

The  Apparatus . — The  electricity  is  generated  by  one  of  two 


WELDING  AND  WELDING  COMPOUNDS. 


437 


methods.  In  the  direct  system  the  dynamo  is  contained  in  the 
machine  below  the  clamps,  and  the  armature  has  two  windings; 
the  one  being  a  fine  winding,  which  is  in  series  with  the  field- 
magnet  coils,  and  the  other  winding  being  merely  a  bar  of  copper 
in  the  form  of  a  letter  U,  or  less  than  a  single  coil.  This  bar  be¬ 
ing  of  a  very  low  resistance,  the  maximum  current  is  sufficient  for 
welding  purposes,  and  the  terminals  are  connected  directly  with 
the  copper  clamps.  Alternating  currents  are  generated  in  this 
machine,  and  used  for  welding,  in  order  to  avoid  commutators, 
which  are  necessary  in  direct-current  machines.  It  should  be  re¬ 
membered  that  in  all  dynamos  the  electricity  is  generated  in 
alternate  currents,  and  that  these  currents  are  in  proper  turn  fed  to 
brushes  of  opposite  polarity,  and  thus  rendered  continuous.  In  an 
alternate-current  dynamo  the  electricity  is  conducted  from  the 
armature  to  rings  instead  of  to  a  commutator,  and  it  is  thus  better 
suited  for  large  currents,  and  some  forms  of  the  apparatus  do  not 
require  rings,  or  any  moving  contacts.  There  is  no  electrical 
reason  why  an  alternating  current  should  be  used  except  the  con¬ 
venience  of  its  manipulation.  In  fact,  the  continuous  current  ap¬ 
plied  by  secondary  batteries  has  been  used  for  this  purpose. 

Another  form  of  apparatus,  termed  the  indirect  system,  is  more 
conveniently  suited  for  large  work,  or  in  places  where  a  number 
of  welding  machines  are  operated  by  the  current  from  a  single 
dynamo.  The  welding  current  is  produced  by  conversion  of  the 
comparatively  high-tension  current  by  means  of  an  inverted  induc¬ 
tion  coil,  termed  a  transformer.  The  primary  circuit  from  the 
dynamo  is  conducted  through  many  turns  of  fine  wire  around  a 
soft  iron  ring,  and  upon  this  same  ring  is  a  single  turn  of  a  large 
copper  bar,  in  which  the  welding  current  is  produced  by  inductive 
effect.  These  currents  receive  4,000  to  15,000  alternations  per 
minute.  The  welding  currents  are  not  changed  suddenly  or  by 
switches,  as  such  manipulation  would  not  be  desirable  or  even 
practicable  with  the  great  currents  used;  but  in  the  direct  welding 
machine  a  set  of  resistance  coils  is  placed  in  the  fine  circuit  which 
passes  around  the  field  magnets,  and  by  interposing  more  or  less 
of  the  resistance  coils  in  this  circuit  the  strength  of  the  magnets 


438 


THE  METAL  WORKER’S  HANDY-BOOK. 


is  diminished  or  increased,  and  the  welding  current  altered  ac¬ 
cordingly. 

With  the  indirect  machine  the  amount  of  the  secondary  or 
welding  current  is  controlled  by  varying  the  current  in  the  primary 
coil  by  means  of  a  kicking  coil,  or  by  a  variable  shunt  in  the  field 
coil,  and  in  other  ways. 

In  either  case  the  apparatus  is  simple,  and  in  full  and  complete 
control  at  will  of  the  operator  by  movement  of  a  lever,  and  this 
action  controls  the  heat. 

The  Process. — In  the  electric  welding  process  the  two  pieces  to 
be  joined  are  secured  in  firm  end  contact  by  a  pair  of  adjustable 
copper  clamps,  which  are  placed  upon  the  top  of  the  apparatus.  An 
electric  current  of  large  volume  is  passed  through  the  pieces,  and 
the  contact  between  them  being  of  less  conductivity  than  the  ho¬ 
mogeneous  metal,  heating  ensues  at  this  place,  as  the  juncture  is 
brought  to  the  proper  temperature  by  the  gradual  motion  of  the 
regulating  lever,  and  as  the  metal  softens  the  clamps  are  pressed 
towards  each  other  to  insure  a  continuous  metallic  union  across 
the  bar. 

The  weld  begins  at  the  centre  and  proceeds  radially  towards  the 
surface,  as  the  temperature  becomes  greater  than  at  the  interior. 
The  heating  is  further  increased  by  the  fact  that  the  resistance  of 
the  hot  metal  is  greater  than  that  of  cold  metal. 

The  enormous  electric  currents  used  in  this  welding  process 
sometimes  reach  50,000  amperes,  but  with  an  electro-motive  force 
of  half  a  volt,  and  therefore  not  capable  of  giving  any  sensation 
to  a  person. 

It  would  be  injudicious  to  offer  any  premium  upon  ignorance, 
but  the  operation  of  electric  welding  is  one  of  the  simplest  of 
mechanical  processes,  requiring  but  little  skill  on  the  part  of  the 
operator  in  comparison  with  that  exact  training  of  hand  and  eye 
and  long  experience  necessary  for  ordinary  welding.  The  operator 
must  understand  the  color  of  the  proper  welding  heat  of  the  metal 
under  treatment,  but  this  is  readily  learned.  The  work  is  not 
manipulated  during  the  process,  except  when  it  is  desired  to  reduce 
the  burr  at  the  weld,  and  is  at  all  times  under  observation,  and  its 


WELDING  AND  WELDING  COMPOUNDS. 


439 


heat  subject  to  entire  control  by  means  of  a  lever  which  graduates 
the  strength  of  the  current. 

The  dynamo  generating  the  electricity  is  self-regulating  and 
requires  no  attention  except  for  lubrication. 

There  is  no  unnecessary  waste  of  fuel,  the  heating  being  local, 
and  does  not  extend  far  from  the  weld  ;  cotton-covered  wire  one- 
fourth  of  an  inch  in  diameter  can  be  welded  without  searing  the 
insulation  over  three-fourths  of  an  inch  from  the  weld. 

The  time  for  making  a  weld  varies  from  a  fraction  of  a  second  to 
about  two  minutes,  according  to  the  work,  although  nothing  over 
two  inches  diameter  has  yet  been  welded  ;  but  larger  machines  are 
in  process  of  construction. 

It  is  not  necessary  to  provide  power  fully  equal  to  the  maximum 
demand,  as  the  time  is  so  short  that  the  momentum  of  a  flywheel 
will  serve  the  same  purpose  as  in  a  drop  press,  and  give  up  the 
surplus  energy  required. 

The  power  is  inversely  porportional  to  the  time,  and  appears  to 
be  about  proportional  to  2.3  power  of  the  diameter  in  inches,  with 
a  slight  variation  of  quick  work  caused  by  differences  in  the  rates 
of  the  thermal  conductivity  of  the  material. 

Applications. — The  process  is  far  cheaper  than  that  of  hand 
welding,  and  also  extends  to  other  methods  of  manufacture,  but 
the  comparative  expense  differs  according  to  the  previous  condi¬ 
tions  in  every  place  where  it  has  thus  far  been  applied. 

Its  applications  in  practical  work  thus  far  have  been  chiefly  con¬ 
fined  to  butt-welding  for  many  purposes,  such  as  continuous  wire 
work,  carriage  work,  axles  and  tires,  cotton-bale  ties,  barrel  hoops 
and  wire  cables  and  many  miscellaneous  purposes.  Axes  are  made 
of  drop  forgings,  joining  the  tool  steel  edge  to  a  mild  steel  poll ;  bars 
are  heated  in  the  middle  and  upset,  forming  collars,  and  pipes  are 
joined  together — a  matter  of  great  value  in  ice  machines.  The 
list  might  be  continued  to  greater  length,  but  this  indicates  the 
range  of  its  practical  uses  at  this  early  day. 

Strength  of  Electric  Welds. — The  value  of  the  process,  for  most 
purposes,  independent  of  any  scientific  interest  or  mechanical  in- 


440 


TITE  METAL  WORKER’S  HANDY-BOOK. 


genuity  shown  in  the  apparatus,  must  be  that  of  the  resistance  of 
the  welds  under  tensile  stress. 

It  will  be  readily  understood,  however,  that  as  this  process  ac¬ 
complishes  many  things  hitherto  impossible,  aside  from  any  question 
of  ultimate  strength,  it  is  fitted  for  applications  in  many  construc¬ 
tions  where  it  saves  labor  and  time,  provided  only  that  the  joints 
be  in  all  cases  sufficiently  good  for  the  purpose  for  which  the 
article  is  designed.  A  large  field  thus  opens  up  in  the  execution 
of  ornamental  design  in  metal  work,  where  it  will  supplant 
screws,  rivets  or  solder  for  fastenings,  and  in  other  evident  applica¬ 
tions. 

Under  the  name  “  electrohephestos  ”  MM.  de  Bernados  and 
Olszewsky  have  patented  a  new  method  of  electrically  welding 
metals,  especially  parts  of  iron.  This  method,  according  to 
“  Dingler’s  Polytechnical  Journal,”  is  in  a  certain  sense  a  comple¬ 
ment  to  Prof.  Thomson’s  process.  While  the  latter  brings  the 
pieces  of  metal  to  be  joined  to  a  welding  heat  and  unites  them  by 
the  use  of  pressure,  thus  forming  an  actual  weld,  Bernados  and 
Olszewsky  melt  the  two  metals  at  their  juncture,  whereby  a  solder¬ 
ing  together  is  effected. 

Extensive  experiments  with  Bernados  and  Olszewsky’s  electric 
welding  apparatus  have  recently  been  made  at  Tegel,  near  Berlin. 
The  process  is  described  as  follows:  The  joint  of  the  two  metals 
which  are  to  be  welded  together  is  connected  with  the  negative 
pole  of  a  dynamo  or  other  source  of  supply,  the  positive  pole  of 
which  is  formed  by  a  carbon  pencil.  Under  the  intense  heat  of 
the  arc  the  most  refractory  metals  melt  almost  instantaneously  at 
their  junction  and  fuse  together.  But  the  action  is  purely  local, 
like  that  of  a  blow-pipe,  and  only  those  parts  upon  which  the  arc 
plays  directly  are  attacked,  the  adjoining  portions  undergoing 
little  change,  and  the  fused  mass  solidifying  and  cooling  very 
quickly.  The  slightness  of  the  chemical  change  produced  by  the 
action  of  the  arc  at  the  joint  is  shown  by  the  appended  table : 


WELDING  AND  WELDING  COMPOUNDS. 


441 


Steel. 

Iron. 

Composition  of  material. 

Before 

welding. 

After 

welding. 

Before 

welding. 

After 

welding. 

Carbon  . . . 

0.48 

0.25 

0-34 

0.14 

Silicon . 

0.04 

Manganese . 

0.50 

0.25 

0.50 

0.23 

Sulphur . 

0.04 

0.04 

9.14 

0.09 

Phosphorus . 

0.08 

0.07 

0.12 

O.II 

Iron . 

98.86 

99  30 

98.90 

99-43 

The  material  requires  little  or  no  preparation.  Even  a  pretty 
thick  layer  of  oxide  will  be  reduced  and  drop  off,  while  smaller 
quantities  of  oxide  unite  to  form  a  slag  with  the  sandy  clay 
frequently  added  as  flux.  This  slag  prevents  the  oxidation  of  the 
metals  while  cooling.  No  other  fluxes  are  required.  The 
operations  can  also  be  carried  on  under  water,  although  the  gases 
and  steam  generated  cause  trouble.  Nevertheless,  an  apparatus  has 
been  constructed  to  facilitate  such  work  by  forcing  the  water  away 
from  the  parts  to  be  treated  by  means  of  compressed  air.  One  of 
the  chief  advantages  claimed  for  the  new  process  appears  to  be 
that  the  arc  is  brought  to  the  work,  and  not  the  work  taken  to 
the  arc,  which  would  mean  transformers,  crucibles,  or  other  apparatus. 
Size  is  hence  a  question  of  secondary  importance,  and  unwieldy 
pieces  may  be  dealt  with,  although  for  soldering  work  of  the 
ordinary  kind  a  special  operating  table  is  employed  as  more  con¬ 
venient. 

In  order  to  obtain  the  various  strengths  of  current  and  E.  M.  F. 
necessary  when  operating  upon  pieces  of  different  size  storage  bat¬ 
teries  are  employed  which  have  been  especially  constructed  for  this 
purpose  by  M.  de  Bernados.  The  complete  cell,  Fig.  25,  weighs 
35  lbs.  and  contains  nine  lead  plates,  Fig.  26,  all  of  the  same  kind, 
four  of  them  positive  and  five  negative,  with  1^  square  yards  of 
total  surface.  Each  plate  consists  of  a  frame  cast  of  pure  lead  6  X 
7 yh  inches  surface  and  0.2  inch  thick.  The  interior  of  the  frame 


442 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


is  filled  with  strips  of  thin  lead,  alternately  straight  and  corrugated, 
Figs.  27  and  28,  soldered  into  their  places;  the  latter  strips  are 
bent  in  such  a  manner  as  to  facilitate  upward  currents  in  the  liquid. 
The  cells  have  an  interior  resistance  of  0.002  ohm  and  give  2.5  volts 
when  continually  charged  while  at  work.  Fifty  to  seventy  of  these 
cells  are  joined  in  a  battery;  several  batteries,  three  for  instance, 
are  grouped  in  parallel  and  are  continually  charged  by  a  shunt 
dynamo.  The  diagram,  Fig,  29,  explains  the  ordinary  connections. 
The  shunt  dynamo  charges  the  fifty  accumulator  cells  in  series ;  a 
voltmetre  and  an  amperemetre  are  inserted  at  Fand  A.  From  the 
positive  terminal  of  every  fifth  cell  a  wire  leads  to  a  plug  switch¬ 
board  U ;  from  U  the  current  passes  through  a  variable  resistance 
W,  and  from  thence  through  a  flexible  cable  to  the  carbon-holder 
Z  and  the  carbon  pencil  K.  The  operator  manipulates  this  carbon- 
holder  Z,  the  metal  to  be  fused  placed  upon  the  table  /"-being 
joined  directly  to  the  negative  terminal  of  the  battery.  By  insert¬ 
ing  the  plug  in  the  switch-board  U  the  operator  may  obtain  cur¬ 
rents  from  five  cells,  and  so  on  to  ten  times  five  cells.  If  con¬ 
siderable  masses  of  metal  are  to  be  dealt  with,  currents  of  con¬ 
siderable  strength  are  needed.  These  are  obtained  by  grouping 
the  batteries  of  certain  sets  of  cells  in  parallel.  Supposing  the 
dynamo  gives  a  current  of  175  volts  and  120  amperes,  that  there  is 
a  battery  of  seventy  cells  coupled  in  series,  and  that  it  is  desired  to 
solder  two  boiler  plates  of  §  inch  thickness.  The  carbon-holder 
is  connected  with  the  positive  terminals  of  the  fortieth  cells  of 
three  groups.  The  carbon  is  allowed  to  touch  for  a  fraction  of  a 
second,  and  is  taken  off  immediately,  so  that  between  the  plates 
and  the  carbon  pencil  an  arc  of  a  few  millimetres’  length  is  formed. 
The  iron  melts  like  wax,  but  the  action  seems  too  powerful,  the 
molten  metal  hissing  and  evaporating  distinctly.  In  such  a  case 
one  of  the  three  parallel  groups  is  cut  out.  Should  the  action  then 
be  too  sluggish,  one  or  more  parallel  groups  is  added.  Sometimes 
the  arc  proves  too  small  or  extinguishes  frequently ;  in  such  cases 
the  number  of  cells  in  each  group  has  to  be  increased. 

The  carbon-holder  (Fig.  30)  resembles  a  pair  of  scissors,  and 
consists  of  two  copper  bars  having  a  round  hole  near  the  end,  in 


WELDING  AND  WELDING  COMPOUNDS, 


443 


444 


TITE  METAL  WORKER’S  II ANDY-BOOK. 


which  the  pencil  is  held  firmly,  either  by  the  friction  of  the  parts 
or  by  means  of  a  little  wedge,  as  shown  in  the  illustration. 

One  of  the  most  important  applications  of  the  new  process  is 
for  welding  plates  of  all  thicknesses.  For  the  very  finest  sheets 
of  one  millimetre  and  less,  the  Electro-Hephestos  Company 
prefer  a  modification  of  Prof.  Thomson’s  process.  But  all 
stronger  plates  up  to  several  centimetres  thickness  are  subjected  to 
the  arc. 

To  effect  this  with  ordinary  plates,  the  edges  are  feathered  as  in 
Fig.  31,  or  Fig.  32,  and  pressed  together.  The  furrows  are  filled 
with  little  pieces  of  the  same  material,  and  the  arc  is  then  applied, 
while  fresh  pieces  are  added  until  the  furrow  is  completely  filled 
with  the  molten  mass.  The  plates  are  immediately  afterwards 
finished  under  the  hammer.  In  making  iron  welds  the  small  pieces 
for  filling  are  always  of  wrought-iron.  With  iron  a  flux  of  clay 
sand  is  recommended  ;  with  copper,  borax  or  sal-ammoniac.  The 
arrangement  (Fig.  32)  secures  great  strength,  but  is  of  course  only 
applicable  when  the  lower  surface  of  the  metal  can  be  got  at. 
When  the  plates  are  joined  on  their  lower  surfaces,  M.  de  Bernados 
suggests  a  powerful  electro-magnet  placed  as  indicated  in  Fig.  33 
to  prevent  the  liquid  metal  (provided  the  material  be  para-magnetic) 
from  flowing  off.  The  apparatus  shown  in  Fig.  34  looks  more 
practical ;  it  is  intended  to  be  employed  when  making  vertical 
seams.  The  pincers  carry  two  pieces  of  graphite  or  coke,  forming  a 
sort  of  chamber  at  the  spot  where  the  fusion  is  to  be  effected. 
As  soon  as  the  mass  has  hardened  sufficiently  the  carbon  pieces  are 
pushed  further  up.  Carbon  pieces  are  frequently  employed  to 
prevent  the  flowing  off  of  the  fused  material.  Figs.  35  to  39  ex¬ 
emplify  other  ways  of  joining  plates  in  cases  where  a  perfectly 
straight  surface  is  not  insisted  upon  ;  for  thinner  plates  the  method, 
Fig.  39,  seems  to  offer  particular  advantages;  for  two  one-fifth-inch 
plates  a  seam  of  a  yard  length  can  be  made  in  seven  minutes. 
When  plates  are  to  be  joined  at  an  angle  the  process  is,  of  course, 
exceedingly  simple. 

This  process  also  permits  of  the  welding  of  dissimilar  metals, 
so  that  iron  and  copper,  zinc,  steel,  cast-iron,  etc.,  can  be  united. 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


445 


XYI. 

WIRE-MANUFACTURE,  BRASSING,  COPPERING,  ELEC¬ 
TROPLATING,  GALVANIZING,  ETC. 

The  process  of  wire-drawing  consists  in  pulling  cold  metallic 
rods  through  perforated  plates  or  “  blocks,”  presenting  a  series  of 
tapering  apertures  of  decreasing  areas,  and  whereby  the  rods  are 
increased  in  length  at  the  sacrifice  of  thickness.  The  ratio  of 
attenuation  is  directly  according  to  the  squares  of  sectional 
diminution  ;  for  example,  by  reducing  a  rod,  say,  one-half,  one- 
third,  or  one-fourth,  etc.,  in  diameter,  its  length  is  respectively 
augmented  four,  nine  or  sixteen  times.  Iron  and  steel  wires  are 
usually  drawn  through  steel-plates,  but  those  of  the  precious  metals 
required  for  the  more  accurate  purposes  of  science  or  the  arts  are 
commonly  drawn  through  perforated  diamonds,  rubies,  or  other 
hard  stones  suitably  mounted  in  the  “blocks,”  and  whereby  great 
lengths  of  fine  wire  can  be  produced  of  uniform  section.  For  a 
long  period  iron  wire  was  very  largely  produced  and  almost  ex¬ 
clusively  used  for  many  purposes,  but,  for  the  last  fifteen  years  or  so, 
steel  has  superseded  its  employment  for  numerous  appliances,  and 
to  a  marked  extent. 

The  drawing  properties  of  metals  are  dependent  upon  the  com¬ 
bined  degrees  of  tenacity  and  ductility — that  is,  the  resistance 
possessed  by  any  body  to  the  separation  of  its  parts,  and  the 
capacity  for  change  of  form  under  the  influence  of  tension  or 
squeezing  pressure  respectively.  Gold,  platinum,  silver  and  iron 
range  highest  in  ductile  notation  ;  whilst  lead,  tin  and  zinc  are 
lowest.  Tenacity  has  more  influence  upon  ductile  efficiency  than 
upon  the  malleability  of  metals.  The  various  uses  to  which  dif¬ 
ferent  wires  are  and  may  be  applied  are  too  numerous  to  define, 
but  amongst  the  most  important,  as  measured  by  quantity  used,  are 
the  following :  For  ropes  for  marine,  mining,  railroad  and  agri¬ 
cultural  purposes  ;  for  fencing,  musical,  bottling,  bale-tying,  brush¬ 
making,  carding,  upholstering,  netting,  electrical  engineering  and 
other  manufacturing  and  scientific  purposes.  With  the  exception 


4-16 


THE  METAL  WORKER'S  HANDY-BOOK. 


of  those  employed  for  electrical  and  scientific  purposes,  the  wires 
would  be  chiefly  composed  of  iron  and  steel.  The  qualities  of 
these  wires  are  commonly  defined  by  such  prefixes  as  charcoal,  iron 
wire,  Bessemer,  basic,  Siemens  and  crucible,  etc.,  steel  wires,  and 
these  may  be  further  characterized  by  the  qualifications — black, 
bright,  annealed,  improved  or  patented,  galvanized,  tinned,  cop¬ 
pered,  etc.  The  first-named  distinctions  simply  denote  the  pro¬ 
cesses  by  which  the  steel  has  been  manufactured,  whilst  other  trade 
conventional  names  indicate  certain  purposes  to  which  the  wire  is 
considered  particularly  applicable,  for  instance,  “plough  steel,” 
which  is  steel  wire  of  high  tensile  strength.  Close  attention  is 
given  to  the  chemical  composition  of  the  ingots  or  blooms  from 
which  the  billets  and  wire  rods  are  rolled.  This  composition 
varies  to  a  known  or  determined  extent,  according  to  the  rods  to 
be  manufactured  ;  it  is  a  branch  which  is  more  or  less  justly  con¬ 
sidered  one  of  the  secrets  of  the  industry.  As  a  general  statement 
it  may,  however,  be  accepted  that  the  various  characteristics  of 
the  different  rods  are  mainly  dependent  upon  the  amount  of  carbon 
present,  and  the  proportionate  admixtures  with  phosphorus,  sul¬ 
phur,  silicon  and  manganese.  When  carbon  is  present  to  the 
extent  of  0.75  to  1  per  cent.,  the  metal  exhibits  remarkable  tensile 
properties  and  capabilities  for  tempering,  also  an  ocult  process  in 
the  trade  which  has  become  quite  an  art ;  for  upon  the  skill  and 
judgment  with  which  this  operation  is  conducted  the  excellency 
of  the  wire  largely  depends.  The  requisite  elimination  or  absence 
of  sulphur,  phosphorus  and  silicon,  is  another  important  considera¬ 
tion,  for  if  present  to  any  improper  extent  the  steel  cannot  be 
worked  with  a  maximum  amount  of  carbon,  whereas  manganese 
favors  the  presence  of  the  latter.  For  different  purposes  the  amount 
of  carbon  present  in  steel  rods  may  range  between,  say  0.075  and  1 
per  cent.,  and  their  hardness  and  tensile  resistance  increase  in  ac¬ 
cordance  with  such  proportions.  The  appreciable  presence  of  sul¬ 
phur  and  phosphorus  is  generally  highly  deleterious,  because  they 
produce  “shortness”  and  unsoundness.  Whilst  excess  of  silicon 
may  impart  similar  properties  and  brittleness  dependent  upon  the 
amount  of  carbon  present,  phosphorus  in  any  quantity  is  an  enemy  to 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


447 


ductility  and  the  process  of  tempering.  From  the  above  remarks 
it  will  be  evident  that  good  wire  rods  can  be  and  are  produced 
from  suitable  crucible  steel,  and  from  Siemens,  Martin  and  Bessemef 
steel.  The  following  are  the  approximate  breaking  strengths  of 
various  wires  in  tons  per  square  inch  : 

Annealed  iron  wire,  25  tons  per  sq.  in.  tensile  resistance. 

Bright  ditto,  35  “  “  “  “  “  “ 

Bessemer  and  basic  steel  wire,  40  “  “  “  “  “  “ 

Mild  Siemens  steel  wire,  60  “  “  “  “  “  “ 

Crucible  cast-steel  wire,  80  to  90  “  “  “  “  “  “ 

Patent  plough,  crucible,  ditto,  100  to  120  “  “  “  “  “  “ 

Wire  rods  are  now  commonly  rolled  from  blooms,  4  inches  to 
10  inches  square,  or  billets,  of  about  2  inches  square,  of  from  50 
to  150  lbs.  each.  At  Garrett’s  wire-rod  mill,  near  Chicago,  Ill., 
rods  are  rolled  direct  from  4-1'nch  blooms  of  120  lbs.  each,  and 
finished  in  one  heat,  the  average  production  per  shift  of  11  hours 
being  about  60  tons,  and  the  largest  week’s  work  about  770  tons. 
In  a  large  wire-rod  mill  in  England  the  billets  used  weigh  mostly 
from  120  to  150  lbs.  each;  but  even  200  lbs.  can  be  manipulated 
at  one  heat.  Unlike  rod  mills  of  the  ordinary  or  old  construction, 
which  have  the  hot  rods  received  on  either  side  of  the  rolls  by 
hands,  which  pass  them  to  and  fro,  the  machine  used  in  these 
works  is  of  more  continuous  action,  and  hands  are  only  required  on 
the  one  side  of  the  mill  to  feed  the  top  set  of  rolls,  and  the  rods 
are  automatically  returned  through  a  lower  series.  The  mill  is 
driven  by  straps  and  a  suitable  gearing,  so  as  to  impart  a  suitable 
velocity  to  each  succeeding  set  of  rolls,  in  order  to  pick  up  the 
slack  or  increasing  lengths  caused  by  rolling  out  the  rods  ;  the  same 
effect  may  also  be  obtained  by  varying  /the  diameter  of  the  rolls. 
The  peripheries  of  the  rolls  are  provided  with  the  decreasing  V, 
U,  and  semicircular  grooves,  for  the  purpose  of  squeezing  out  and 
kneading  the  metal  into  as  compact  and  homogeneous  a  form  as  pos¬ 
sible  as  it  passes  through  them.  The  various  rolls  are  capable  of 
accurate  adjustment  to  insure  each  set  reducing  the  rod  to  the  re¬ 
quired  diameter,  and  the  last  of  the  series  rolling  exactly  to  a 
desired  gauge. 


448 


TTTE  METAL  WORKER’S  HANDY-BOOK. 


Rods  are  usually  rolled  down  to  a  No.  5  English  legal  standard 
wire  gauge,  but  for  smaller  sizes  of  wire  they  are  sometimes  re¬ 
duced  to  a  No.  8  gauge  in  order  to  diminish  the  labor  of  wire¬ 
drawing  and  also  effect  a  saving  in  the  annealing  department. 
During  the  rolling  process  before  described  the  metal  may  be 
squeezed  through,  say,  twelve  or  fifteen  sets  of  rolls,  i.  e.,  a  dozen 
or  more  consecutive  “  passes  ”  are  commonly  made  from  the  billet 
to  the  finished  rod  at  one,  two  or  more  heats,  according  to  the 
efficiency  of  the  mill  and  general  arrangements.  Fig.  40  shows 
the  entire  series  of  grooves  of  a  wire-rod  roll.  The  construction 

o>  O  O  <=>  <>  o  O  <=>  o  00 

Fig.  40. 

of  an  oval  groove  will  be  seen  from  Fig.  41.  The  width  of  the 
groove  b  is  the  diagonal  of  a  square,  from  the  corners  of  which  the 
two  arcs  are  described  which  terminate  the  oval  groove.  It  is  then 
b  —  1. 414  r,  and  h  =  0.5858  r. 


During  the  process  of  rolling  the  particles  or  molecules  of  the 
metal  are  more  or  less  squeezed  or  forced  into  abnormal  positions, 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


449 


thus  impairing  the  uniform  temper  of  the  rods  ;  but  this,  however, 
is  commonly  counteracted  by  subsequent  annealing  or  reheating,  so 
as  to  allow  the  molecules  to  resume  their  normal  relations.  The 
length  of  finished  rods  may  vary  from  60  to  150,  and  up  to  500 
yards  in  one  piece,  naturally  dependent  upon  the  gauges,  materials 
and  weights  they  are  produced  from.  For  example,  a  No.  5  gauge 
rod,  0.212  in.  in  diameter,  rolled  from  a  billet  weighing  1  cwt., 
would  be  about  320  yards  in  length,  and  this,  if  subsequently 
drawn  down  to  No.  20  gauge  wire,  0.036  inch  in  diameter,  would 
equal  some  11,200  yards  in  length,  without  any  appreciable 
diminution  in  weight.  The  gauge  referred  to  is  in  all  cases  the 
“  English  legal  standard.” 

After  the  rods  leave  the  “blooming  mill  ”  they  are  taken  to  the 
“wire  mill,”  where  they  are  hung  around  wooden  blocks,  perhaps 
half  a  dozen  coils  on  each  block,  which  are  lowered  into  huge  tubs 
of  sulphuric  acid,  and  allowed  to  remain  there  until  the  acid  has 
removed  the  impurities  from  the  surface.  The  blocks  are  then 
raised  by  a  pulley,  and  the  rods  are  thrown  upon  the  floor  and 
washed  with  the  hose.  Having  been  loaded  on  trucks  and  dried, 
one  end  of  each  rod  is  pointed  by  a  revolving  machine  so  as  to 
obtain  tapering  rods  capable  of  being  introduced  into  the  conical 
apertures  in  the  draw-plate.  In  some  cases  the  rods  after  having 
been  freed  from  impurities  are  dipped  in  lime-water,  which  assists 
the  process  of  drawing,  and  finally  are  placed  in  a  drying  room  or 
chamber. 

A  wire-drawing  mill  consists  of  a  series  of  horizontal  drums  or 
pulleys — termed  “blocks” — mounted  on  vertical  axes  upon  long 
benches  with  draw-plates  and  pincer  devices  attached  to  each.  The 
draw-plates,  which  are  pierced  with  a  regular  gradation  of  tapering 
holes,  are  held  in  vices  or  clamping  frames  firmly  fixed  to  the 
bench,  whilst  the  mechanical  pincers  are  provided  for  catching 
hold  of  the  tapering  extremities  of  the  rods  inserted  in  the  holes 
of  the  plates  for  pulling  them  through,  the  pairs  of  pincers  being 
forced  back  by  revolving  cones  fixed  on  the  drum  spindles.  When 
a  sufficient  length  of  any  rod  has  thus  been  drawn  to  enable  a  turn 
being  taken  round  a  revolving  pulley  or  drum,  the  drawing  process 
29 


450 


THE  METAL  WORKER’S  HANDY-BOOK. 


is  continued  by  this  means,  the  turning  of  each  of  the  series  of 
pulleys  drawing  one  of  the  various  rods  through  the  steel  plates  or 
draw-blocks,  and  thereby  increasing  their  lengths  by  reducing  their 
thickness. 

Fig.  42  represents  a  wire-drawing  mill.  A  is  the  reel  upon 
which  the  wire  is  wound  ;  b  the  draw-iron  held  in  the  frame  B,  the 
finely  hatched  portion  consisting  of  steel.  C  is  the  drum.  The 
shaft  f  with  the  pulley  i  revolves  constantly,  whilst  when  running 
empty  the  drum  stands  still.  When  the  drum  is  to  revolve,  it  is 
lifted  up  by  means  of  a  treadle  at  f ;  the  hook  o  catches  the  drum 
and  takes  it  along.  When  the  wire  c,  which  winds  up  spirally,  has 


A  c 


entirely  passed  through  the  draw-iron  the  tension  ceases,  the  drum 
falls  down,  and,  being  liberated  from  the  hook  0,  comes  to  a  stand¬ 
still  without  the  co-operation  of  the  workman. 

The  wire  drawn  upon  any  drum  may  have  to  be  re-drawn  in  a 
similar  manner  a  number  of  times  dependent  upon  the  gauge  re¬ 
quired,  the  process  being  facilitated  by  the  application  of  lubri¬ 
cants,  termed  “wire-drawers’  soap  and  grease,”  as  the  wire  is 
pulled  through  the  decreasing  holes  in  the  draw-plate.  Lubrica¬ 
tion,  as  commonly  practised,  consists  in  applying  a  paste  made  of 
wheat  flour  or  lime  to  the  surface  of  the  wire  to  be  drawn,  and  when 
the  paste  is  dry  to  smear  the  wire  with  tallow  or  grease ;  the  wire 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


451 


is  then  ready  to  be  drawn,  the  dried  paste  serving  to  prevent  the 
lubricant  from  being  pressed  out  in  the  process.  Some  manufac¬ 
turers  use  in  drawing  fine  wire  a  lubricant  consisting  of  sour  beer 
yeast  and  a  layer  of  olive  oil.  F.  Vogel  recommends  the  following 
fat  pickle :  Melt  a  determined  quantity  of  lard  or  similar  sub¬ 
stance,  and  after  cooling  it  to  about  1250  F.  add,  with  constant 
stirring,  20  to  40  per  cent,  of  66  per  cent,  sulphuric  acid  until  the 
mass  is  of  the  consistence  of  soft  soap ;  then,  with  continued 
stirring,  add  water  until  the  mixture  is  completely  dissolved  in  the 
water.  By  adding  sulphuric  acid  as  well  as  water  the  mass  becomes 
again  heated,  and  hence  sufficient  provision  for  cooling  must  be 
made.  The  application  of  this  very  fat  fluid  lubricant  is  claimed 
to  facilitate  the  drawing  of  wire  to  such  an  extent  that  annealing 
during  drawing  is  not  so  often  required  as  in  the  ordinary  process. 
It  is  further  claimed  that  the  draw-irons  do  not  wear  out  so 
quickly,  that  the  wire  acquires  a  higher  lustre  and  does  not  rust  so 
readily. 

Chas.  H.  Morgan  recommends  the  use  of  a  hot  solution  of  lime 
and  salt  as  a  lubricant  in  drawing  Bessemer  wire.  By  using  the 
solution  at  a  boiling  temperature  the  water  is  quickly  thrown  off, 
when  the  wire  is  taken  from  the  bath  and  kept  in  a  warm  dry 
place  until  it  is  drawn.  Salt  coating,  whether  combined  with  lime 
or  otherwise,  is  claimed  to  resist  any  pressure  that  steel  wire  of  the 
highest  tensile  strength  makes,  when  being  drawn,  upon  the  inner 
surface  of  the  die. 

As  the  drawing  operations  proceed  the  wire  becomes  proportion¬ 
ally  hardened  and  its  original  properties  altered  so  that  it  has  to 
be  annealed  at  certain  stages  of  the  process.  In  practice  wire  to 
be  drawn  to  a  fine  gauge  is  sometimes  returned  to  the  annealing 
pot  about  half  a  dozen  times.  During  the  process  of  drawing  some 
wire  may  be  placed  on  reels  mounted  in  tubs  of  acid  and  other 
solutions  for  cleaning  off  any  coat  of  oxide  formed  by  annealing. 
The  annealing  pots  are  simply  metal  chambers  into  which  the  wire 
is  placed  and  hermetically  sealed  during  the  process  of  heating  for 
several  hours  at  a  red  heat,  and  which  afterwards  is  allowed  gradu¬ 
ally  to  cool  down.  An  average-sized  pot  receives  about  50  per 


452 


THE  METAL  WORKER’S  HANDY-BOOK. 


cent,  of  wire  at  one  charge.  Finally  annealed  or  tempered 
wires  are  always  softer  and  more  pliable  than  those  bright-finished 
or  drawn  ;  steel  wire,  however,  requires  different  treatment  from  that 
employed  for  iron.  To  avoid  the  formation  of  scales  during  an¬ 
nealing,  which  cannot  be  entirely  prevented,  even  with  the  use  of 
hermetically  sealed  pots,  W.  Rath  immerses  the  wire  before  an¬ 
nealing  in  a  solution  of  calcium  chloride  of  the  consistence  of 
syrup.  The  protecting  coat  which  is  thereby  formed  upon  the 
wire  is  removed  after  annealing  and  cooling  by  rinsing  in  clean 
water. 

The  drawing-drums  before  referred  to  are  of  various  sizes — say 
from  32  inches  to  10  inches  diameter,  and  maybe  driven  at  a  speed 
of  about  300  to  400  feet  per  minute  for  ordinary  wire ;  steel  wire 
should  be  drawn  at  a  slower  speed  in  order  to  prevent  breakages. 
The  drums  used  for  taking  the  first  draws  on  the  rough  rods  are 
termed  “ripping  blocks”  and  are  of  large  diameter  and  strong 
construction,  whilst  the  speed  of  driving  is  usually  rather  lower 
than  that  above  mentioned ;  but  this,  however,  is  dependent 
throughout  upon  the  sizes  of  the  blocks  and  the  classes  of  wire  to 
be  drawn.  The  drums  of  small-sized  blocks  may  be  driven  at  a 
velocity  of  500  feet  or  more  per  minute  for  drawing  soft  wire. 
When  the  holes  in  the  drawing-irons  have  become  enlarged  by 
wear  the  plates  are  heated  and  hammered  up  and  partially  re¬ 
punched,  the  requisite  diameters  of  the  holes  being  ascertained  and 
adjusted  by  the  insertion  of  gauge  punches.  Some  kinds  of  wires 
are  tempered  or  “  patented  ”  before  drawing;  others  during  or 
after  this  process,  in  order  to  promote  or  develop  a  uniform  temper 
or  flexibility,  and  few  processes  are  conducted  less  according  to 
fixed  rules  or  with  more  secrecy,  as  nothing  but  experience  can 
initiate  one  into  this  important  branch  of  the  industry.  In  every 
case,  however,  it  is  necessary  that  the  rods  or  wire  be  raised  to  a 
definite  temperature  in  a  furnace  chamber  or  “muffle”  before  the 
cooling  and  fixing  process  is  commenced,  and  which  is  somewhat 
determined  by  the  colors  the  metal  assumes  by  oxidation  during 
the  progress  of  treatment. 

The  finally  prepared  wires  of  the  required  gauges  are  then 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


453 


formed  into  bundles  or  coils  of  convenient  dimensions  and  re¬ 
moved  to  the  store-room  ready  for  transport  or  use. 

As  regards  wires  from  other  metals  than  iron  and  steel  it  re¬ 
mains  to  be  said  that  they  are  generally  drawn  from  small  square 
blocks  cut  from  sheet.  The  strips  are  rounded  off  in  the  draw- 
iron  and  gradually  drawn  out  to  the  desired  diameter.  Annealing 
is  more  or  less  required  with  all  metals ;  copper  requires  but  little, 
it  being  very  ductile. 

Half-round  Wire. — Schniewindt  produces  half-round  wire  by 
splitting  round  wire  by  means  of  rotatory  shears.  The  wire  is 
wound  upon  a  reel  a,  Fig.  43,  and  passes  through  the  rolls  b, 


which  are  provided  with  corresponding  grooves  to  a  guide  f.  The 
latter  feeds  the  wire  to  the  circular  knives  in  such  a  manner  that  it 
is  cut  through  longitudinally  in  the  direction  of  its  axis  and  wound 
upon  the  two  receiving  reels  d  and  d’ . 

Barbed  Wire. — This  variety  of  wire  consists  of  wire  cords,  or 
even  single  wires,  provided  with  projecting  sharp  barbs  placed  at 
short  distances  from  each  other.  It  is  at  present  much  used  for 
fencing  of  all  kinds.  As  regards  shapes  and  dimensions  barbed 
wire  varies  very  much  ;  a  number  of  typical  shapes  are  shown  in 
Fig.  44.  Varieties  A  to  C  consist  of  two  galvanized  steel  wires 


454 


THE  METAL  WORKER’S  II ANDY-BOOK. 


0.098  inch  in  diameter,  which  are  twisted  into  a  cord  and  provided 
with  sharp-pointed  barbs.  The  latter  are  formed  of  a  piece  of 
wire  cut  obliquely  on  both  ends  and  wrapped  twice  around  the 
cord.  On  A  the  barbs  are  4^  inches  apart,  on  B  2^  inches,  and 
on  C,  which  is  provided  with  four  barbs,  5^  inches.  Variety  D 
consists  of  three  steel  wires,  between  which  are  placed  sharp  sheet- 
steel-points  projecting  in  all  directions,  there  being  about  24  such 


points  for  every  3^  feet.  E  shows  barbed  fencing  wire  manufac¬ 
tured  by- Bernhard  Ebeling,  of  Bremen.  It  consists  of  two  steel 
wires  0.098  inch  in  diameter  twisted  together  and  provided  through¬ 
out  their  entire  length  with  an  insertion  of  a  strip  of  notched  hoop- 
iron.  Another  variety  manufactured  by  C.  Klauke,  of  Miincheberg, 
near  Berlin,  consists  of  a  single  wire  only.  It  is  made  by  a  machine 
especially  constructed  for  the  purpose.  A  short  piece  of  wire  is 


WIRE — MANUFACTURE,  BRASSING,  ETC. 


455 


first  shaped  as  shown  in  J,  Fig.  44,  which  is  then  connected  with 
the  principal  wire  in  the  manner  illustrated  by  F  and  H.  This 
arrangement  is  inferior  to  the  shapes  A  to  D,  the  wire  being  less 
solid  and  the  barbs  pointing  only  in  two  directions. 

Moen  has  patented  a  machine  for  the  manufacture  of  barbed 
wire,  which  is  shown  in  Fig.  45.  Around  a  wire  is  wrapped  a  strip 
of  sheet-iron,  one  edge,  or  both  edges,  of  which  is  provided  with 
oblique  incisions  which,  in  wrapping  and  bending  the  strip  of  sheet- 
iron,  form  the  barbs.  The  strip  of  sheet-iron  rolled  up  is  placed 
upon  the  wrapping  contrivance  R  and  reaches  by  means  of  the 
guide  v  w  the  progressing,  but  not  revolving  wire.  N  and  O  are 


conducting  rolls,  B  is  the  drum  for  impulsion  and  is  connected  with 
the  arms  P  and  Q,  while  J  is  the  drum  for  carrying  away  the 
finished  barbed  wire. 

Barbed  wire  has  also  been  manufactured  from  a  single  wire  with¬ 
out  any  addition.  Fig.  44  G  shows  such  a  barbed  wire  consisting 
of  spirally  twisted  hoop-iron  the  edges  of  which  are  provided  with 
sharp  incisions,  which  in  twisting  form  projecting  barbs.  Finally 
the  “  Westphalische  Union,”  of  Hamm,  manufactures  an  oval  wire 
0.31  inch  wide  and  o.ri  inch  in  diameter,  which,  as  shown  in  the 
illustrations  K  and  Z,  Fig.  44,  is  provided  on  the  sides  with  sharp 
incisions.  By  turning  up  the  points  thus  made  barbs  are  formed 
which  are,  however,  rather  short,  stand  quite  obliquely  and  only 
alternately  on  two  sides. 

Barbed  wire  is  brought  into  commerce  wound  upon  a  wooden 
reel. 


456 


THE  METAL  WORKER’S  HANDY-BOOK. 


Phosporized  Bronze  or  Brass  Wire. — Whiting,  of  Manchester, 
England,  manufactures  phosphorized  bronze  or  brass  wire  by  im¬ 
mersing  stout  wire  of  the  above-mentioned  or  other  alloys  in  a 
solution  of  0.125  to  5  Per  cent-  of  phosphorus  in  ether,  bisulphide 
of  carbon  or  olive  oil,  5  to  10  per  cent,  of  sulphuric  acid  and  85 
to  95  per  cent,  of  water,  whereby,  it  is  claimed,  the  metal  absorbs 
phosphorus.  The  wire  is  then  drawn  one  number  finer  and  brought 
into  a  closed  retort,  the  bottom  of  which  is  covered  with  a  thin 
layer  of  phosphorus,  so  that  the  vapors  of  phosphorus  evolved  can 
pass  over  the  wire.  The  latter  is  then  packed  in  charcoal,  and  the 
charcoal  being  ignited  the  wire  is  kept  in  the  heat  until  sufficiently 
softened  to  allow  of  being  drawn  one  number  finer.  Wire  thus 
repeatedly  treated  is  claimed  to  possess  great  resisting  power  and 
acquire  a  high  polish. 

Hardening  of  Wire. — Frequently  it  is  desirable  to  harden  wire, 
especially  steel-wire,  in  coils.  For  this  purpose  the  coil  is  placed 
upon  a  reel  from  which  the  wire  is  conducted  in  a  horizontal  direc¬ 
tion  to  and  wound  upon  a  second  reel  placed  at  some  distance 
from  the  first.  In  its  passage  to  the  second  reel  the  wire  passes 
through  between  a  pair  of  plates  4  to  6  feet  long,  lying  in  a  furnace 
and  kept  at  a  red  heat,  and  is  next  conducted  through  between  a 
similar  pair  of  plates  cooled  by  water.  The  plates  of  each  pair  are 
provided  with  suitable  grooves  for  the  reception  of  the  wire ;  a 
third  pair  of  plates  is  moderately  heated  and  serves  for  tempering 
to  the  desired  degree  of  hardness.  Instead  of  the  centre  pair  of 
plates  a  reservoir  filled  with  water  or  oil  is  sometimes  used  for 
cooling. 

Ramsden’s  Method  of  Hardening  Wire  differs  somewhat  from  the 
above.  The  wire  is  conducted  through  pipes,  in  which  it  is  heated 
by  the  flame  of  an  inflammable  mixture  of  carburetted  hydrogen 
gas  and  steam,  and  then  passes  into  a  cooling  bath. 

For  heavier  wires  two  small  pipes  are  arranged  at  a  right-angle 
to  each  other,  the  one  being  placed  in  a  horizontal  and  the  other 
in  a  vertical  position,  and  their  mouth-pieces  provided  with  narrow 
apertures.  The  free  end  of  the  horizontal  pipe  connected  by  means 
of  a  cock  or  valve  with  a  steam-pipe,  and  the  lower  end  of  the 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


457 


vertical  pipe  with  a  vessel  filled  with  a  hydrocarbon,  for  instance, 
paraffine  or  petroleum.  A  current  of  steam  being  conducted 
through  the  horizontal  pipe  absorbs,  in  passing  by  the  mouth-piece 
of  the  vertical  pipe,  carburetted  hydrogen  and  carries  it  along  in  a 
finely  divided  state  and  intimately  mixed  with  the  steam.  Of  such 
pairs  of  mouth-pieces  a  sufficient  number  for  the  production  of  the 
necessary  degree  of  heat,  which  can  be  regulated  by  a  cock,  are 
arranged  in  front  of  a  cylinder  lined  with  fire  clay,  so  that  the  flame 
entirely  freed  from  smoke  and  other  injurious  substances  passes 
through  the  chamber  into  the  chimney.  Now  if  the  chamber  is 
about  13  feet  long  the  heat,  where  the  flame  enters,  will  be  con¬ 
siderably  greater  than  where  it  passes  out,  and  thus  the  apparatus 
can  be  used  in  the  front  part  for  hardening  and  in  the  back  part 
for  tempering.  The  chamber  rests  upon  a  vessel  divided  into  two 
parts,  one  division  of  which  may  be  filled  with  cold  water  or  a 
frigorific  mixture.  The  wire  being  unwound  from  a  reel  passes 
through  the  front  part  of  the  chamber,  and  after  being  conducted 
through  the  fluid  is  again  wound  upon  a  reel.  For  tempering  the 
wire  may  then  be  conducted  through  the  back  part  of  the  chamber, 
and  from  there  into  the  other  division  of  the  vessel,  which  con¬ 
tains  water,  oil  or  a  suitable  fatty  mixture. 

For  finer  wires  and  such  as  are  not  to  come  in  contact  with  the 
flame  a  pipe  of  fire-clay  about  13  feet  long  is  used  ;  it  may  be  with¬ 
out  a  partition,  or  divided  into  an  upper  and  lower  chamber.  In 
the  latter  case,  the  lower  chamber  is  heated  while  the  wire  passes 
through  the  upper.  When  coming  from  the  latter  it  is  struck  by  a 
jet  of  oil  or  other  suitable  fluid,  and  tempering  is  effected  by  im¬ 
mersing  it  in  a  bath  of  a  suitable  boiling  fluid,  for  instance  lin¬ 
seed  oil  at  536°  F. ,  or  mercury  at  the  same  temperature,  or  in 
melted  lead,  the  adhering  lead  being,  in  the  latter  case,  removed. 
Fig.  46  I  shows  the  arrangement  for  coarser  and  //  and  III  for 
finer  wires.  On  the  chamber  of  the  first  the  mouth-pieces  B  and 
C,  provided  with  the  cock  D,  connect  with  the  reservoir  of  car¬ 
buretted  hydrogen  E  and  the  steam  conduit ;  G  is  the  reel  upon 
which  the  wire  to  be  hardened  is  wound.  The  wire  W  passes 
through  an  aperture  into  the  front  part  of  the  chamber,  which  is 


458 


THE  METAL  WORKER’S  HANDY-BOOK. 


strongly  heated,  then  underneath  the  first  roll  Trover  a  second  roll, 
through  an  aperture  in  the  bottom  of  the  chamber  into  the  divi¬ 
sion  beneath  and  finally  upon  the  reel  Gu  the  latter  dipping  into 
the  reservoir  H,  which  is  filled  with  water  or  a  refrigorific  mixture. 
The  wire  while  passing  the  two  rolls  i^in  the  chamber  Ax  is  heated 
and  hardened  by  dipping  in  the  fluid  in  H.  To  facilitate  the  con¬ 
ducting  of  the  cold  wire  over  the  rolls  F,  before  the  chamber  is 
heated,  apertures  Au  for  passing  the  rolls  through,  are  provided  on 
the  upper  portion  of  the  chamber,  which,  after  the  wire  is  placed 
in  position,  are  closed  by  the  lid  Ax.  The  superfluous  heat  is  con¬ 
ducted  away  from  the  chamber  A  through  the  chimney  P,  and  the 
reel  Gl  with  the  hardened  wire  is  taken  from  the  reservoir  H  and 
placed  in  K  over  the  chamber  A.  From  here  the  hardened  wire 
W  passes  into  the  rear  or  chimney  end  of  the  chamber  Au  in 
which  the  heat,  having  been  moderated  by  the  bridge  J,  is 
much  less,  but  sufficient  to  heat  the  wire  running  over  the  rolls 
F,  for  tempering.  The  wire  is  then  wound  upon  the  reel  K 
which  dips  into  the  oil  in  the  reservoir  H,  whereby  the  wire  is 
tempered. 

For  finer  kinds  of  wire  the  retort  or  heating  chamber  M,  Fig. 
46  II  to  IV,  is  divided  lengthwise  into  two  parts  by  the  partition 
N.  On  the  front  side  of  the  chamber  are  apertures  Olt  opposite  to 
each  a  pair  of  mouth-pieces  is  arranged.  The  flame  entering  at 
O  sweeps  along  the  lower  side  of  IV  through  the  holes  C  into  the 
upper  part  of  the  chamber.  The  wire  is  introduced  into  the  upper 
part  of  chamber  at  the  end  .Si  and  heated  while  passing  through  it. 
The  heat  is  retained  in  the  upper  portion  of  the  chamber  by  the 
lids  L.  These  lids  are  arranged  on  each  end  of  the  upper  cham¬ 
ber  so  as  to  leave  room  to  allow  of  the  passage  of  the  wire.  On 
leaving  the  retort  the  wire  is  hardened  by  dipping  in  a  current  of 
oil  running  over  the  sloping  plate  6".  The  oil  flows  uninterruptedly 
from  the  pipe  T,  which  is  connected  to  a  reservoir,  runs  over  the 
sloping  plate  5  into  the  holder  Tu  and  from  there  is  pumped  back 
into  T.  The  hardened  wire,  in  order  to  acquire  the  necessary 
temperature,  then  passes  through  a  bath  U  of  linseed  oil,  mercury 
or  lead,  which  is  heated  by  a  fire.  After  passing  through  the  bath 


WIRE — MANUFACTURE,  BRASSING,  ETC. 


459 


U  it  is  wound  upon  ordinary  reels  arranged  in  a  suitable  position 
near  the  bath  U.  To  facilitate  the  introduction  of  the  cold  un¬ 
tempered  wire  into  the  retort  before  heating,  a  channel  or  gutter 
is  provided  on  the  upper  side  of  the  retort.  The  wire  is  conducted 
through  this  channel  or  gutter,  which,  later  on,  is  closed  by  the  lid 


Mv  The  superfluous  heat  is  conducted  away  through  the  chim¬ 
ney  X. 

The  following  tables  relating  to  wire  are  furnished  by  John  A. 
Roebling’s  Sons  Co.,  of  Trenton,  N.  J. 


4G0 


THE  METAL  WORKER’S  HANDY-BOOK. 


Wire  Gauges,  . 

In  Deci7tial  Parts  of  an  Inch. 


Number  of 
wire  gauge. 

Roebling. 

Brown  & 
Sharpe. 

Birming¬ 
ham,  or 
Stubs. 

English 

Legal 

Standard. 

Old  English, 
or  London. 

oooooo 

ooooo 

oooo 

.46 

•43 

•393 

.46 

•454 

.464 

•432 

■4 

•454 

ooo 

.362 

.40964 

•425 

•372 

•425 

oo 

•33i 

.3648 

.380 

•348 

•38 

o 

•3°  7 

•32495 

•340 

■324 

•34 

i 

•2S3 

•2893 

•3 

•3 

•3 

2 

.263 

.25763 

.284 

.276 

.284 

3 

•  244 

.22942 

.259 

.252 

•  259 

4 

.225 

.20431 

.238 

.232 

.238 

5 

.207 

.18194 

.22 

.212 

.22 

6 

.192 

.  1 6202 

•203 

.192 

.203 

7 

.177 

.14428 

.18 

.176 

.18 

8 

.162 

.12849 

.165 

.16 

.165 

9 

.148 

•  H443 

.148 

.144 

.148 

IO 

•135 

.10189 

•134 

.128 

•134 

1 1 

.12 

.09074 

.12 

.Il6 

.12 

12 

.105 

.08081 

.109 

.104 

.IO9 

13 

.092 

.07196 

.095 

.O92 

•095 

14 

.08 

.06408 

.083 

.08 

•083 

'5 

.072 

.05706 

.072 

.072 

.072 

l6 

.063 

.05082 

.065 

.064 

.065 

17 

.054 

.04525 

.058 

.056 

.058 

18 

•C47 

.0403 

.049 

.048 

.049 

19 

.041 

.03589 

.O42 

.04 

•04 

20 

•035 

.03196 

•035 

•036 

•035 

21 

.032 

.02846 

•032 

•032 

•0315 

22 

.028 

02534 

.028 

.028 

.0295 

23 

.025 

.02257 

.025 

.024 

.027 

24 

.023 

.0201 

.022 

.022 

•025 

25 

.02 

.0179 

.02 

.02 

•023 

26 

.018 

.01594 

.018 

.018 

•0205 

27 

.017 

.OI4I9 

.016 

.0164 

.01S75 

28 

.016 

.01264 

.014 

.0148 

.0165 

29 

.015 

01 125 

.013 

.0136 

•0155 

30 

.014 

.01002 

.012 

.0124 

•01375 

3i 

•0135 

•00893 

.OIO 

.0116 

.01225 

32 

.013 

.00795 

.OO9 

.0108 

.01125 

33 

.OI  I 

.00708 

.008 

.OI 

.01025 

34 

.OI 

•0063 

.007 

.OO92 

.0095 

35 

.0095 

.00561 

.005 

.0084 

.OO9 

36 

.OO9 

.005 

.OO4 

.0076 

.0075 

WIRE— MANUFACTURE,  BRASSING,  ETC. 


461 


Table  Indicating  Size,  Weight,  and  Length  of  Iron  and 

Steel  Wire. 


Gauge 

number. 

Diameter. 

Inches. 

Weight  of 
100  feet. 
Pounds. 

Weight  of 
one  mile. 
Pounds. 

Feet  in  2000 
pounds. 

Area. 

Square  inches 

3-° 

.362 

34-73 

1834 

5*759 

.102921 

2-0 

■331 

29.04 

15  33 

6,886 

.086049 

1-0 

•307 

25.00 

I3l8 

8,000 

.074023 

I 

.283 

21.23 

II2I 

9.425 

.062901 

2 

.263 

18.34 

968 

10,905 

•054325 

3 

.244 

15.78 

12,674 

.046759 

4 

.225 

13-39 

707 

I4.936 

.039760 

S 

.207 

h-35 

599 

17,621 

•033653 

6 

.192 

9-73 

5H 

20,555 

.028952 

7 

.177 

8.30 

439 

24,906 

.024605 

8 

.162 

6.96 

367 

28,734 

.0206 1 2 

9 

.148 

5.80 

306 

34,483 

.017203 

IO 

•135 

4-83 

255 

41,408 

•014313 

II 

.120 

3.82 

202 

52,356 

.011309 

12 

.105 

2.92 

154 

68,493 

.008659 

13 

.092 

2.24 

1x8 

89,286 

.006647 

14 

.080 

1.69 

89 

”8,343 

.005026 

15 

.072 

i-37 

72 

145-985 

.004071 

l6 

.063 

1.05 

55 

190,476 

.003117 

17 

•054 

•77 

4i 

259,740 

.002290 

iS 

.047 

.58 

31 

344,827 

•001734 

19 

.041 

•45 

24 

444,444 

.001320 

20 

-°35 

■32 

17 

625,000 

.000962 

21 

.032 

.27 

14 

740,741 

.000804 

22 

.028 

.21 

I  I 

952,381 

.000615 

23 

.025 

•  *75 

9.24 

.000491 

24 

.023 

.140 

7-39 

.000415 

25 

.020 

.Il6 

6.124 

.000314 

26 

.018 

•093 

4-9 1 

.000254 

27 

.017 

.083 

4.382 

.000227 

28 

.016 

.074 

3-907 

.000201 

29 

.015 

.061 

3.22 

.000176 

30 

.014 

.054 

2-851 

.OOOI54 

31 

•0135 

.050 

2.64 

.000143 

32 

.013 

.046 

2  428 

.000132 

33 

.OI I 

•037 

1  953 

.000095 

34 

.OIO 

.030 

1.584 

.000078 

35 

.0095 

.025 

1.32 

.OOOC7I 

36 

.OO9 

.021 

1.161 

.000064 

462 


THE  METAL  WORKER’S  HANDY-BOOK. 


Weight  per  iooo  Feet  of  Copper  Wire. 


Number. 

Roebling. 

Brown  & 
Sharpe. 

Birmingham. 

English 

legal 

standard. 

oooooo 

ooooo 

641.20 

560.29 

652.39 

565-51 

oooo 

468.02 

641.20 

624.58 

484.83 

ooo 

397-09 

508.49 

547-33 

4*9-33 

oo 

332.00 

403.26 

437-56 

366.97 

o 

2S5.60 

322.79 

350.29 

3*8  10 

I 

242.69 

253.61 

272.72 

272.72 

2 

209.60 

201.13 

244.07 

230  83 

3 

180.41 

*59-49 

203.27 

*92-43 

4 

153-39 

126.49 

I71  64 

163.09 

5 

129.84 

IOO.3I 

146.66 

136.19 

6 

hi. 71 

79-54 

124.87 

hi. 71 

7 

94-93 

63  08 

98.18 

93.86 

8 

79  52 

50-03 

82.50 

77-57 

9 

66.37 

39.68 

66.37 

62.83 

IO 

55.22 

3*46 

54-4* 

49.65 

1 1 

43-63 

24-95 

43-63 

40.77 

12 

334i 

19.79 

36.00 

32-77 

*3 

25  65 

15-69 

27-35 

25-65 

14 

19-39 

12.44 

20.87 

*9-39 

15 

15-71 

9.S7 

15.71 

15.71 

16 

12.03 

7-83 

12.80 

12.41 

17 

8.84 

6.20 

10.19 

9  50 

is 

6.69 

4-92 

7.27 

6.98 

19 

5.09 

3-90 

5-34 

4.85 

20 

3  7i 

3-10 

3-7* 

3-93 

21 

3.10 

2.45 

3-'° 

3  *0 

22 

2.38 

i-94 

2.38 

2.38 

23 

1.S9 

*45 

1.89 

1.74 

24 

1.60 

1.22 

147 

*47 

25 

1. 21 

.970 

1. 21 

1. 21 

26 

.981 

.770 

.981 

.981 

27 

.876 

.610 

•776 

.815 

28 

.776 

.484 

•594 

.664 

29 

.682 

-384 

.512 

•560 

3° 

•594 

•3°4 

436 

.466 

3i 

•552 

.241 

•303 

.408 

32 

.512 

.191 

.245 

•353 

33 

.366 

•*52 

.194 

-3°3 

34 

•303 

.120 

.148 

.256 

35 

.273 

-095 

.076 

.214 

36 

•245 

.076 

.048 

•*75 

WIRE— MANUFACTURE,  BRASSING,  ETC. 


463 


Weight  per  Mile  of  Copper  Wire. 


Number. 

Roebling. 

Birmingham. 

Brown  & 
Sharpe. 

English 

legal 

standard. 

OOOO 

2466 

3286 

3375 

2555 

OCX) 

2092 

2884 

2677 

2210 

00 

1750 

2305 

2123 

1933 

0 

1504 

1846 

1684 

1682 

I 

1278 

1437 

1335 

1437 

2 

1104 

1287 

1058 

1216 

3 

950 

1071 

839 

1012 

4 

808 

9°4 

665 

860 

5 

684 

773 

528 

718 

6 

588 

657 

418 

588 

7 

500 

517 

332 

495 

8 

419 

435 

263 

409 

9 

350 

350 

209 

332 

10 

291 

287 

166 

263 

11 

230 

230 

131 

215 

12 

176 

190 

104 

173 

13 

135 

144 

83 

135 

14 

102 

no 

65 

102 

15 

83 

83 

S2 

83 

l6 

64 

68 

41 

65 

17  * 

47 

53^ 

33 

5° 

18 

35 

38 

26 

37 

19 

27 

28 

20^ 

26 

20 

19  Vz 

19K 

i6* 

20^ 

21 

16* 

13 

16X 

22 

I2>! 

ioy 

12K 

23 

i°X 

i°X 

9^ 

24 

8X 

rA 

6^ 

lA 

25 

6^ 

ey2 

5^ 

6  y2 

26 

5 

5 

4 

5 

27 

4^ 

4 

3k( 

4 

28 

4 

3% 

2% 

3^ 

29 

3  H 

2% 

2 

3 

30 

3% 

2  X 

1# 

2'/z 

To  Brass  Wire  in  the  Galvanic  Way. — To  carry  out  this  process 
place  the  iron  rods  intended  for  wire  in  a  bath  containing  3  parts 
of  ordinary  tin  salt  to  4  of  blue  vitriol.  The  rods  must  only  pass 
once  through  the  draw-iron  and  be  previously  zincked  by  immersing 
them  for  2  hours  in  water  acidulated  with  hydrochloric  acid  in 
which  zinc  plates — 1  to  1.5  lb.  of  zinc  to  100  lbs.  of  iron — are 


464 


TITE  METAL  WORKER’S  HANDY-BOOK. 


placed.  The'  rods  are  left  in  the  brass  bath  for  5  to  6  minutes 
until  they  have  acquired  a  dirty  reddish  color;  by  passing  through 
the  draw-iron  they  assume  a  fine  straw-color  or  orange-yellow 
surface. 

To  Electro-brass  Wire. — A  warm  bath  in  an  iron  boiler  lined 
with  sheet  brass  is  used.  The  sheets  of  brass  are  connected  to  the 
copper  pole  of  the  battery  and  dipped  into  the  fluid.  The  bundles 
of  iron  wire  are  first  opened,  dipped  into  sulphuric  acid,  then  sus¬ 
pended  to  a  strong  wooden  peg  and  scoured  with  a  brush  and 
sharp  sand.  They  are  next  placed  over  a  strong  copper  or  brass 
rod  resting  upon  the  edge  of  the  boiler  and  insulated  therefrom  by 
means  of  rubber  tubes  and  connected  to  the  zinc  pole  by  the  bat¬ 
tery.  The  wires  now  receive  a  coating  of  copper  and  then  a  de¬ 
posit  of  brass.  As  they  are  only  partly  submerged  in  the  bath 
they  must  from  time  to  time  be  turned.  They  are  finished  by 
washing  and  drying  in  saw-dust.  The  bath  is  prepared  as  follows: 
Dissolve  blue  vitriol,  4^  ozs.,  and  sulphate  of  zinc,  4)4  to  5)4 
ozs.,  in  1  gallon  of  water.  Precipitate  the  solution  with  2  lbs.  of 
crystallized  soda,  decant  and  wash.  Then  pour  a  solution  of  1  lb. 
of  soda  and  8)4  ozs.  of  sodium  bisulphate  in  1  gallon  of  water 
over  the  precipitate.  Stir  the  mixture  and  add  commercial  potas¬ 
sium  cyanide  until  the  fluid  becomes  clear,  when  it  is  filtered  off 
from  the  suspended  ferric  oxide.  The  best  temperature  for  using 
this  bath  is  between  120°  and  140°  F. 

Brass  Wire  which  may  be  drawn  out  to  the  finest  threads  is 
made  by  placing  round  rods  of  copper  about  1  inch  in  diameter 
and  2)4  inches  long  free  in  an  iron  box,  upon  the  bottom  of  which 
are  laid  granulated  zinc  and  sal-ammoniac.  By  heating  the  box 
vapors  arise  which  combine  with  the  copper  and  superficially  con¬ 
vert  it  into  brass.  The  coating  is  made  as  uniform  as  possible  by 
frequently  turning  the  rods.  In  this  manner  copper  rods  are  ob¬ 
tained  which,  so  to  say,  are  plated  with  brass  and  may  be  drawn 
out  to  fine  wires.  The  wires  have  the  appearance  of  brass,  but  on 
the  cross  section  the  red  color  of  the  copper  can  be  recognized. 

To  Copper  Iron  Wire. — This  process  is  claimed  to  prevent  the 
rusting  of  iron  wire;  it  is  partially  effected  by  dipping  and 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


465 


partially  by  galvanic  action.  Dissolve  at  86°  F.,  3.3^  drachms  of 
blue  vitriol  in  55  lbs.  of  water  containing  1.12  drachms  of  sul¬ 
phuric  acid.  Pass  the  iron  wire  through  the  cold  solution  until  it 
is  covered  with  a  coating  of  copper.  It  is  then  drawn  through  an 
ordinary  draw-iron  to  make  the  coating  of  copper  adhere  more 
firmly.  Repeat  the  dipping  and  subsequent  passing  through  the 
draw-iron  several  times.  Galvanic  coppering  is  effected  as  follows  : 
Connect  the  wire  to  the  negative  pole  of  a  battery  and  a  copper¬ 
plate  with  the  positive  pole.  As  coppering  fluid  a  solution  of  39 
ozs.  of  potassium  cyanide  and  88  ozs.  of  potassium  bichromate  in 
55  lbs.  of  water  is  used  ;  the  bath  should  have  a  temperature  of 
between  48  and  550  F.  By  the  action  of  the  galvanic  current  the 
copper  is  dissolved  from  the  positive  pole  and  forms  the  copper 
solution,  from  which  the  copper  is  deposited  upon  the  wire  con¬ 
nected  with  the  negative  pole.  The  coppered  wire  is  passed  through 
the  draw-iron.  Iron  wire  may  in  the  same  manner  be  tinned, 
zincked  and  coated  with  lead. 

To  Galvanize  Wire. — The  wire,  previously  made  bright  by  pick¬ 
ling,  is  passed  through  a  cast-iron  crucible  containing,  according  to 
the  quantity  and  size  of  the  wire,  from  40  to  1,000  lbs.  of  melted 
zinc,  and  then  passed  through  the  draw-iron  to  remove  the  super¬ 
fluous  zinc.  The  drawing  through  the  bath  is  effected  by  unwind¬ 
ing  the  wire  from  a  reel  set  in  motion  by  a  steam-engine,  the 
velocity  depending  on  the  diameter  of  the  wire,  it  being  more 
rapid  with  thin  wire  and  slower  with  thick  wire. 

An  apparatus  for  this  purpose,  patented  by  Roberts,  is  shown  in 
Fig.  47.  C  is  a  guide  pulley,  the  block  of  which  is  provided  with 
the  protecting  plate  J,  having  a  guide  slit ;  it  can  be  shifted  on  two 
rods  F,  reaching  up  to  the  ceiling  of  the  work-room.  On  these 
rods  F  slides  a  block  A1,  with  pulley  D,  provided  below  and  above 
with  rope  loops.  To  the  lower  of  these  loops  is  fastened  a  hand- 
rope,  and  to  the  upper  another  rope  AT,  running  over  the  pulley 
G,  which  is  secured  in  the  ceiling  ;  to  the  rope  H,  is  suspended 
the  counterweight  I,  which,  when  the  running  block  is  on  top, 
stands  upon  the  floor.  A*  is  a  guide  pulley  resting  in  a  frame. 
The  wire  /«  runs  from  the  reel  B  around  C  over  D  and  underneath 
30 


THE  METAL  WORKER’S  IIANDY-BOOK. 


466 


P  into  the  acid  bath,  from  there  into  a  furnace  and  the  metallic 
bath,  and  from  here  through  the  polishing  machine  to  the  reel  upon 
which  it  is  to  be  wound.  With  this  apparatus  many  wires  can  at 
the  same  time  be  treated. 

Vogt  has  patented  an  arrangement  (Fig.  48)  for  closing  vessels 


through  which  the  wire  is  to  be  conducted  in  a  straight  direction. 
It  consists  of  two  elastic  strips  f  which,  on  tightening  the  screws 
g,  are  pressed  together  by  the  metallic  bodies  e. 

For  the  purpose  of  removing  superfluous  zinc  Wittle  and  Kamper 
have  patented  the  arrangement  shown  in  Fig.  49.  It  consists  of 


Fig.  48. 


two  comb-like  plates  a  a,  one  of  which  remains  stationary  during 
the  operation  while  the  other  is  secured  to  a  rotary  lever  c. 

Another  apparatus  for  the  same  purpose,  patented  by  Roberts,  is 
constructed  as  follows:  Upon  the  edge  of  the  crucible,  where  the 
wire,  m  (Fig.  50)  leaves  the  zinc  bath,  sits  an  iron  box  K,  which  is 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


467 


provided  with  a  slit  for  the  passage  of  the  wire.  In  the  box  two 
rolls  Z,  with  longitudinal  ribs  /,  revolving  in  opposite  directions 
by  means  of  a  driving  gear  placed  outside  the  box.  These  rolls  L 
are  so  mounted  that  two  ribs  l  always  come  opposite  to  each  other, 
with  sufficient  space  between  them,  however,  to  allow  of  the  pas¬ 


sage  of  the  wire  m.  Outside  of  the  box  K  are  two  revolving  rolls 
P,  which,  by  means  of  the  eccentric  P',  and  the  sliding  rods  R,  sets 
the  springy  stoppers  T  moving  to  and  fro.  To  attain  the  springi¬ 
ness  of  the  stoppers  T,  they  are  composed  of  a  rod  R',  hollow  on 
the  end,  into  which  catches  the  sliding  rod  B,  and  the  actual 


stopper  T,  which  slides  in  a  cavity  provided  with  a  spring.  To 
prevent  the  stopper  T  from  falling  out  it  is  provided  with  a  pin  T' , 
running  in  a  groove.  The  box  K  is  filled  with  mineral  wool,  which 
by  the  rolls  L  is  pressed  with  a  certain  force  against  the  wire  m 
coming  from  the  metallic  bath  Z,  and  thus  cleans  it. 


468 


THE  METAL  WORKER’S  II ANDY-BOOK. 


To  Gild  Metallic  Wire  and  Wire-cloth. — Fine  wire  of  gilded 
copper  and  brass  is  much  used  in  the  manufacture  of  metallic 
fringes,  and  lace  for  epaulets  and  other  purposes.  The  fine  copper 
and  brass  wires  being  drawn  through  the  drawing,  machines  and 
wound  upon  spools  by  special  machines,  and  hence  not  touched  by 
the  hands,  freeing  from  grease  may  generally  be  omitted.  The  first 
.requisite  for  gilding  is  a  good  winding  machine,  which  draws  the 


F'g-  5'- 


wires  through  the  gold  bath  and  wash-boxes,  and  further  effects  the 
winding  of  the  wire  upon  spools.  The  principal  demand  made  in 
the  construction  of  such  a  machine  is,  that  by  means  of  a  simple 
manipulation  a  great  variation  in  the  speed  with  which  the  wire  or 
gauge  passes  through  the  gold  bath  can  be  obtained.  This  is  nec¬ 
essary  in  order  to  be  able  to  regulate  the  thickness  of  the  gilding 
by  the  quicker  or  slower  passage  of  the  wire.  A  machine  well 
adapted  for  this  purpose  is  the  one  constructed  by  J.  W.  Spaeth. 
The  variation  in  the  velocity  of  the  passage  of  the  wire  is  attained 
by  the  two  friction-pulleys  A  (Fig.  51)  which  sit  upon  a  common 


WIRE— MANUFACTURE,  BRASSING,  ETC 


469 


shaft  with  the  driving-pulley  R,  and  transmit  their  velocity  by 
means  of  the  friction-pistons  K  K  to  the  friction-pulley  F \  which 
is  firmly  connected  to  the  belt-pulley  R  driving  the  spool-spindle. 
Since  by  a  simple  device  the  pistons  K  and  K  may  be  shifted,  it  is 
clear  that  the  transmission  of  the  number  of  revolutions  from  F  to 
F  is  dependent  on  the  position  of  the  friction-pistons  K  and  K, 
and  that  the  velocity  will  be  the  greater  the  shorter  the  distance  they 
are  from  the  centre  of  the  friction-pulleys  F  and  F.  In  order  that 
the  friction  between  F  K  and  F  may  always  be  sufficient  for  the 
transmission  of  the  motion,  even  when  the  pistons  are  worn,  four 
weights  G  are  provided,  which  press  the  above-mentioned  parts 
firmly  against  each  other. 

In  front  of  each  spool  of  this  machine  is  inserted  a  small  en¬ 
amelled  iron  vat  which  contains  the  gold-bath,  and  is  heated  by  a 
gas-flame  to  about  167°  F.  Between  this  bath  and  the  winding 
machine  is  another  small  vat  with  hot  water  in  which  the  gilded 
wire  is  rinsed. 

The  wires  unwind  from  a  reel  placed  in  front  of  the  gold  bath, 
run  over  a  brass  drum  which  is  connected  to  the  negative  pole  of 
the  source  of  current,  and  transmits  the  current  to  the  wires ;  the 
dipping  of  the  wires  into  the  gold  bath  is  effected  by  porcelain 
drums  which  are  secured  to  heavy  beams  of  lead  placed  across  the 
vats,  as  shown  in  Fig.  52.  The  gilded  wire  being  wound  upon  the 


spools  of  the  winding  machine,  these  spools  are  removed  and 
thoroughly  dried  in  the  drying  chamber.  The  wire  is  then  again 
reeled  off  on  to  a  simple  reel,  in  doing  which  it  is  best  to  pass  it 
through  between  two  soft  pieces  of  leather  to  increase  its  lustre.  The 
most  suitable  formula  for  the  gold  bath  is  as  follows:  Fine  gold  in 
the  form  of  fulminating  gold,  15.43  grains;  98  per  cent,  potassium 


470 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


cyanide,  77.16  grains;  water,  1  quart.  The  bath  is  prepared  by 
converting  15.43  grains  of  fine  gold  into  neutral  chloride  of  gold 
by  dissolving  in  aqua  regia  and  evaporating,  or  29.3  to  30.8  grains 
of  chemically  pure  neutral  chloride  of  gold  are  directly  dissolved 
in  water ;  the  gold  is  precipitated  as  fulminating  gold  with  aqua 
ammonia,  washed  out,  dissolved  in  water  containing  the  potassium 
cyanide  and  heated,  with  constant  replacement  of  the  water  lost  by 
evaporation,  until  the  odor  of  ammonia  disappears.  The  tempera¬ 
ture  of  the  bath  should  be  between  158°  and  167°  F.  Strength  ofcur- 
rent  6  to  8  volts,  which  will  produce  a  deposit  of  sufficient  thickness 
even  with  the  wire  passing  at  the  most  rapid  rate  through  the  bath. 

Gold  Wire  is  made  by  wrapping  a  very  thin  sheet  of  gold  around 
a  cylinder  of  silver,  securing  it  with  wire,  heating,  and,  while  still 
hot,  rubbing  vigorously  with  the  burnisher,  and  immediately  pass¬ 
ing  through  the  draw-iron.  The  ductility  of  gold  is  so  great  that 
wire  as  thin  as  a  spider’s  web  appears  completely  coated  with  gold 
when  examined  under  the  microscope. 

To  Nickel  Wire. — Nickelling  of  wire  of  iron,  brass  or  copper  is 
scarcely  done  on  a  large  scale ;  it  is,  however,  believed  that  the 
nickelling  of  iron  and  steel  wires — for  instance,  piano  strings — 
might  be  of  advantage  to  prevent  rust  or  at  least  to  retard  the  com¬ 
mencement  of  oxidation  as  long  as  possible. 

To  nickel  single  wires  cut  into  determined  lengths  according  to 
the  general  rules  is  simple  enough ;  but  this  method  cannot  be 
pursued  with  wire  several  hundred  yards  long  rolled  in  coils  as  it 
occurs  in  commerce.  Nickelling  the  wire  in  coils,  however,  can¬ 
not  be  done,  as  only  the  upper  windings  exposed  to  the  anodes 
would  acquire  a  coat  of  nickel.  Hence  it  becomes  necessary  to 
unwind  the  coil,  and  for  continuous  working  pass  the  wire  at  a  slow 
rate  through  the  cleansing  and  dipping  baths  as  well  as  the  nickel 
bath  and  hot- water  reservoir,  as  shown  in  Fig.  54  in  cross-section 
and  in  Fig.  55  in  ground-plan. 

The  unwinding  of  the  wire  is  effected  by  a  slowly  revolving  shaft 
upon  which  the  nickelled  wire  again  coils  itself ;  in  the  illustration 
this  shaft  is  omitted.  In  Fig.  54  four  wires  run  over  the  four  rolls 
a,  mounted  upon  a  common  shaft  to  the  rolls  b  upon  the  bottom 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


471 


of  the  vat  A,  whereby  they  come  in  contact  with  a  thickly-fluid 
lime-paste  in  the  vat  and  are  freed  from  grease.  From  the  rolls  b 
the  wires  run  through  the  wooden  cheeks  lined  with  felt,  which 
retain  the  excess  of  adhering  lime-paste  and  allow  it  to  fall  back 
into  the  vat.  The  wires  then  pass  over  the  roll  c  to  the  roll  d. 
Between  these  two  rolls  is  the  rose  g,  which  throws  a  strong  jet  of 
water  upon  the  wires,  thereby  freeing  them  from  the  adhering  lime- 
paste.  The  roll  d,  as  well  as  its  axis,  is  of  brass,  and  to  the  latter 
is  connected  the  negative  pole  of  the  battery  or  dynamo,  so  that 
by  carrying  the  wires  over  the  roll  d  negative  electricity  is  conducted 
to  them.  From  the  roll  d  the  wires  run  over  the  roll-bench  s  (Fig. 
54)  to  the  vat  C,  which  contains  the  nickel  solution,  so  that  they 
are  subjected  to  the  action  of  the  anodes  arranged  in  this  vat  on 
both  sides  of  the  wires.  The  wires  then  pass  over  the  roll  e,  are 
rinsed  under  the  rose  s,  and  run  finally  through  a  hot-water  reservoir 
and  saw-dust  (these  two  apparatuses  are  not  shown  in  the  illustration), 
to  be  again  wound  into  coils.  In  case  a  high  polish  is  required  the 
nickelled  wires  may  be  run  under  pressure  through  leather  cheeks 
dusted  with  pulverized  Vienna  chalk. 

To  Tin  Wire  and  Wire-gauze. — Allow  the  wire  to  run  slowly 
into  a  wooden  trough  which  contains  a  mixture  of  3  parts  of  water 
and  1  or  1.75  of  hydrochloric  acid;  then  rinse  it  in  water,  dry  by 
passing  it  between  two  rolls  covered  with  felt  or  coarse  woollen 
stuff,  and  finally  pass  it  under  a  roll  placed  in  a  vessel  containing 
strongly-heated  tin.  To  polish  the  wire  coming  from  the  zinc, 
pass  it  through  between  rolls  covered  with  woollen  stuff  dusted 
with  chalk  powder.  Wire-gauze  is  pickled  in  a  similar  manner, 
and  after  rinsing  in  water  the  adhering  water  is  removed  by  wiping 
with  cloths.  The  wire  is  then  dusted  with  finely  powdered  resin 
inclosed  in  a  bag,  the  gauze  placed  upon  a  frame  and  immersed  in 
the  tin  bath,  where  it  remains  1  to  2  minutes,  when  it  is  lifted  out 
and  the  excess  of  tin  removed  by  shaking  the  frame.  Especially 
fine  tinning  of  iron  wire  is  produced  as  follows  :  Place  the  wire  in  a 
wooden  vessel  of  suitable  size,  which  contains  water  mixed 
with  to  per  cent,  of  hydrochloric  acid,  and  upon  the  bottom  of  which 
zinc  plates  are  placed.  After  a  short  time  a  gray  coating  of 


472 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


metallic  zinc  is  formed  upon  the  wire,  when  it  is  brought  into  the 
tin  bath.  The  latter  is  prepared  by  suspending  2  parts  of  tin-salt  in  a 


WIRE— MANUFACTURE,  BRASSING,  ETC. 


473 


bag  in  a  vessel  containing  a  solution  of  2  parts  of  tartaric  acid  in  100 
of  water.  The  tin-salt  being  dissolved,  stir  the  fluid  until  the  white 
precipitate  formed  is  dissolved,  and  then  add  in  small  portions  a 
solution  of  3  parts  of  soda.  In  consequence  of  the  development 
of  carbonic  acid  vigorous  effervescence  takes  place  and  a  white 
precipitate  separates.  The  fluid  is  now  allowed  to  rest  until  clear, 
when  it  is  drawn  off,  and  the  wire,  which  has  been  previously  con¬ 
nected  to  zinc  plates,  is  immersed  in  the  tin-bath  for  2  or  3 
hours.  The  tin  deposits  as  a  dead-white  coating  capable  of  a  high 
polish;  the  wire  need  only  be  passed  once  through  the  draw-iron 
in  order  to  acquire  a  beautiful  lustre  and  to  make  the  coating  of  tin 
to  adhere  firmly.  Small  articles  of  iron  may  be  readily  tinned  by 
previously  providing  them  with  a  thin  coat  of  copper.  This  is 
effected  by  first  immersing  the  bright  articles  in  a  boiling  solution 
of  chloride  of  zinc,  and,  when  they  have  acquired  a  coating  of 
zinc,  in  a  copper  bath  melted  under  a  cover  of  borax.  The 
articles  being  thinly  coppered  may,  with  the  assistance  of  sal- 
ammoniac,  be  readily  provided  with  a  firmly-adhering  deposit  of 
melted  tin. 

To  Harden  Steel  Piano  Wire. — Heat  the  steel  wire  to  a  red  heat, 
and  then  cool  in  the  ordinary  manner.  Then  immerse  it  in  a 
metal  bath  composed  of  lead  40  parts,  zinc  12,  antimony  26,  tin 
21,  and  bismuth  1.  The  bath  should  be  heated  somewhat  above 
its  melting  point,  and  the  wire  allowed  to  remain  in  it  until  it  has 
acquired  the  temperature  of  the  bath,  which  takes,  of  course,  a 
longer  time  the  thicker  the  wire  is.  When  taken  from  the  bath 
cold  water  is  sprinkled  or  poured  over  the  wire.  The  hardening 
and  tempering  above  described  are,  as  a  rule,  effected  immediately 
before  the  last  drawing,  and  only  after  the  last  drawing,  when  the 
wire  is  not  required  to  be  bright. 

Coating  which  does  not  Oxidize  Readily  upon  Steel  and  Iron  Wire. 
— Villiers  produces  such  a  coating  by  immersing  the  wire  in  a 
weak  acid  solution,  and  after  thoroughly  washing,  drying  it  at  176° 
F.  The  wire  is  then  immersed  in  a  fluid  alloy  of  tin  90  parts, 
lead  9,  and  silver  1,  rinsed  in  cold  water  and  dried. 


474 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


XVII. 

MISCELLANEOUS. 

Manufacture  of  Basic  Open-hearth  Steel. — In  experiments  made 
by  J.  H.  Darby,  four  12-ton  and  afterwards  two  20-ton  furnaces 
were  used.  Each  furnace  is  provided  with  a  separate  chimney, 
ordinary  butterfly  reversing  valves  of  ample  size,  and  regenerator 
chambers  of  large  capacity.  The  furnace  proper  is  composed  of 
two  wrought-iron  sides,  supported  by  H  iron  buck-staves,  well 
braced  together  at  the  top  and  bottom.  The  ends  are  left  open  ; 
holes  are  cut  in  the  plates  for  the  three  doors  on  the  front  side  of 
the  furnace,  and  another  hole  is  made  at  the  back  for  the  tap-holes. 
The  plates  are  also  cut  away,  to  allow  air  to  circulate  for  cooling 
purposes  under  the  furnace  bottom  and  bridge  plates.  The  silica 
blocks  at  each  end  of  the  furnace  are  built  in  the  usual  manner. 
The  roof  is  level  from  block  to  block;  the  ends,  however,  are 
well  inclined,  to  bring  the  flame  down  on  the  metal.  On  the  iron 
plates  for  holding  the  dolomite  hearth  fire-bricks  are  placed,  so 
that  no  part  of  the  basic  hearth  when  finished  is  more  than  15 
inches  thick.  As  soon  as  all  the  brick-work  is  dry,  hard-burnt  dolo¬ 
mite,  well  ground  and  mixed  with  as  little  anhydrous  tar  as  is  needed 
to  make  it  stick  together  when  compressed,  is  rammed  with  hot 
irons  until  the  desired  shape  of  the  hearth  is  built  up;  the  tap-hole 
is  made  by  a  round  piece  of  wood,  which  is  left  in  and  burnt  out 
as  the  furnace  heats  up.  The  shrunk  dolomite  or  basic  material  is 
brought  up  to  the  bottom  of  the  doors  and  to  an  equal  height  all 
round.  On  it  a  layer  of  about  2  inches  chrome  ore,  also  ground 
fine  and  mixed  with  tar,  is  rammed  to  act  as  a  neutral  separator 
between  the  acid  and  the  basic  portions ;  chrome  ore  is  also 
rammed  in  between  the  silica  blocks  and  the  basic  hearth.  The 
side  walls  and  jambs  are  built  on  the  chrome  ore.  The  roof  is 
then  put  on  and  the  furnace  heated  up,  at  first  with  a  coal  fire. 
When  the  furnace  is  properly  dried  and  heated  the  hearth  will  be¬ 
come  very  hard  ;  the  tap-hole  should  be  cleaned  out,  and  then 
filled  with  dry,  ground,  basic  material  for  several  inches.  This 
should  be  well  pushed  up  against  a  scraper  held  from  the  middle 


MISCELLANEOUS. 


475 


door.  Anthracite  coal  is  then  rammed  in,  and  the  outside  of  the 
tap-hole  is  covered  with  damp  sand.  The  charge  may  now  be 
introduced.  Mr.  Darby  uses  80  per  cent,  of  pig  and  20  per  cent, 
of  scrap.  Limestone  is  usually  charged  in  sufficient  quantity  to 
make  a  basic  slag  from  the  first,  scrap  and  pig  follow.  When 
sufficiently  hot,  additions  of  iron  ore  and  limestone  are  made  at  ‘ 
intervals  during  about  five  hours.  The  first  sample  is  taken,  and 
from  its  appearance  and  fracture  it  is  judged  if  sufficient  ore  has 
been  added.  If  so,  as  much  as  possible  of  the  unspent  oxide  is 
reduced  in  the  slag  by  reacting  on  the  remaining  impurities,  lime 
additions  being  from  time  to  time  made.  The  hammered  sample 
rapidly  improves.  The  edges,  which  were  at  first  rough,  become 
smooth  and  free  from  cracks ;  the  surface  of  the  sample  is  clean, 
and  when  the  charge  is  ready  it  will  bend  over  into  four  thicknesses 
without  any  indication  of  cracking.  Ferro-manganese  is  then 
added,  and  the  charge  is  teamed.  Any  kind  of  iron  ore  may  be 
used  in  the  steel  furnaces,  providing  it  contains  a  low  percentage 
of  silica.  The  20-ton  furnaces  make  from  180  to  200  tons  of 
ingots  per  week,  or  23.3  cwt.  per  hour,  exclusive  of  Sundays. 
After  experience  in  the  manufacture  of  over  60,000  tons  of  basic, 
open-hearth  steel,  Mr.  Darby  has  never  seen  red-short  material  in 
the  usual  soft  quality.  An  average  analysis  of  the  soft  steel  is  as 
follows : 

C  =  .12  p.  c.,  P=  .03,  S  =  .018,  Si  =  nil,  Mn  =  .400. 

This  steel  gives  about  24.5  tons  tensile  strain  per  square  inch 
and  15  tons  elastic  limit,  with  an  elongation  of  31  to  33  per  cent, 
in  8  inches. 

The  Carlsson-Bessemer  Process. — The  Carlsson  modification  of 
the  Bessemer  process  is  employed  in  Sweden  in  the  treatment  of  a 
charcoal  pig-iron  containing  about  1.5  per  cent,  of  silicon,  0.1  to 
0.15  of  manganese,  3.9  of  graphite  and  o.  1  of  combined  carbon. 
The  slag  produced  in  the  production  of  this  pig-iron  approximates 
more  closely  to  a  trisilicate  than  a  bisilicate,  alumina  being  con¬ 
sidered  as  a  base-  After  the  pig-iron  has  been  charged  into  the 


476 


THE  METAL  WORKER’S  II ANDY-BOOK. 


converter,  it  is  blown  for  about  5  or  6  minutes,  until  the  blue  flame 
appears  that  marks  the  commencement  of  the  combustion  of  the 
carbon.  The  blow  is  then  stopped,  and  a  definite  proportion  of 
the  charge,  varying  with  the  quality  of  the  metal  it  is  desired  to 
produce,  is  poured  into  a  ladle  of  peculiar  construction,  so  arranged 
as  to  show  the  weight  of  the  metal  charged  into  it,  the  slag  being 
carefully  removed.  This  portion  of  the  charge  usually  contains 
4.15  per  cent,  of  carbon,  0.05  of  silicon  and  0.07  of  manganese. 
The  remaining  portion  of  the  metal  in  the  converter  is  then  blown 
until  most  of  the  carbon  has  been  eliminated  and  the  bath  con¬ 
verted  into  malleable  iron.  The  portion  of  the  metal  previously 
removed,  together  with  any  necessary  additions  required  for  special 
purposes,  is  then  added  to  the  bath.  When  the  reaction  that 
ensues  is  ended  the  metal  is  ready  for  pouring.  Before  this  addi¬ 
tion  is  made,  the  bath  usually  consists  of  metal  containing  a  trace 
of  silicon,  0.03  per  cent,  of  manganese,  0.05  per  cent,  of  carbon 
and,  as  a  maximum,  0.02  of  sulphur.  As  this  metal  is  usually  red- 
short,  some  rich  manganese  iron  is  added  before  the  addition  of 
the  second  portion  of  the  metal  from  the  ladle.  The  percentage  of 
silicon  in  the  final  product  is  usually  about  one-tenth  of  that  of  the 
carbon,  so  that  steel  containing  0.2  of  carbon  would  also  contain 
0.02  of  silicon. 

Malleable  Cast-iron. — The  custom  among  most  malleable  iron 
makers  is  to  use  such  irons  only  as  are  quite  free  from  phosphorus 
and  sulphur,  for  the  reason  that  the  process  in  use  is  designed  es¬ 
pecially  to  eliminate  carbon,  and  after  they  have  driven  that  out 
they  have  no  desire  to  leave  anything  remaining  which  will  make 
the  metal  brittle.  By  the  use  and  mixture  of  certain  brands  of 
iron  they  have  the  means  of  converting  their  product  into  almost 
pure  wrought-iron. 

The  melting  is  now  done,  on  the  large  scale,  in  reverberating  fur¬ 
naces,  and  the  iron  is  purified,  to  a  certain  extent,  while  in  a  molten 
condition  by  directing  into  the  heating  chamber  a  current  of  at¬ 
mospheric  air  which  mixes  with  the  products  of  combustion.  In 
its  essential  principles  the  method  has  a  resemblance  to  Berard’s 
process  of  steel-making — the  gaseous  currents  of  air  or  of  the  fur- 


MISCELLANEOUS. 


477 


nace  may  be  used,  as  occasion  requires,  alternately,  but  the  tuyeres 
are  not,  like  his,  provided  with  apparatus  for  adjustment.  The 
process  of  removing  impurities  from  the  metal  must  not  be  carried 
so  far  as  to  detract  from  its  fluidity  at  the  temperature  at  which  it 
is  to  be  poured.  These  facts  control  the  operation ;  the  purer  the 
metal  is  the  higher  is  its  melting  point,  and  whatever  impurities 
are  allowed  to  remain  must  be  such  as  may  either  be  removed  by 
subsequent  operations  or  such  as  may  be  allowed  to  exist  in  the 
finished  product.  The  useful  function  of  the  impurities  is  to  lower 
the  melting  point  in  the  scale  of  temperature.  Small  test  pieces, 
of  a  finger’s  length,  are  cast  from  time  to  time  until  the  right 
point  is  reached,  as  determined  by  the  appearance  of  their  fracture. 
The  metal  is  then  ready  to  be  poured  into  the  moulds,  and  as 
these  will  hold  no  large  amount  the  pouring  is  generally  done  from 
hand  ladles.  After  the  cast  pieces  are  removed  from  the  sand  and 
have  the  risers,  runners  and  sprues  knocked  from  them,  they  are 
rattled  in  tumbling  barrels  to  remove  the  adhering  sand  and  scale 
and  to  expose  the  naked  surface  of  the  material  to  the  ready  access 
of  the  chemical  agents  of  decarbonization. 

The  cast-iron  pieces,  hard  and  brittle,  are  now  ready  for  the 
process  which  will  alter  them  in  their  whole  nature  without  sub¬ 
jecting  them  to  any  physical  force.  The  process  is  one  of  disso¬ 
ciation  of  the  compound  cast-iron,  which  is  carburet  of  iron  ;  the 
carbon  has  purposely  been  made  to  appear  in  its  combined  form 
and  is  not  visible  as  graphite ;  the  iron,  when  broken,  exhibits  a 
fine  white  appearance  of  the  fractured  surface,  with  a  suggested  in¬ 
dication  of  lines  radiating  from  the  centre. 

The  pieces  are  packed  in  cast-iron  boxes  with  the  rust  or  oxide 
of  iron.  These  boxes  are  round  or  square,  according  to  the  shape 
of  the  work.  If  round,  they  are  perhaps  2  feet  in  diameter,  and, 
if  rectangular,  they  may  be  2  feet  long,  1  y2  feet  wide  and  1  foot 
high.  When  these  are  filled  rims  of  the  same  size  are  placed  on 
them,  increasing  the  height  another  foot,  and  when  these  are  filled 
another  rim,  and  still  another  is  added,  until  the  box  is  4  feet  in 
depth,  packed  full  of  castings  and  oxidizing  metal.  This  material 
may  be  wrought-iron  turning-chips  which  have  been  rusted  by  be- 


478 


TIIE  METAL  WORKER’S  HANDY-BOOK. 


ing  spread  upon  a  hot  floor,  where  they  were  sprinkled  with  a  solu¬ 
tion  of  sal-ammoniac. 

After  the  boxes  are  packed  they  are  placed  in  a  double  row  in 
brick  chambers  or  ovens,  which  are  large  enough  to  contain  twenty. 
The  aperture  through  which  they  were  carried  in  is  now  walled  up, 
and  fire  is  admitted  to  the  chamber  from  a  furnace  at  one  side. 
The  flames  fill  the  chamber  and  pass  out  to  the  flue  on  the  opposite 
side.  The  firing  is  continued  for  3  days  or  longer,  if  required, 
and  the  work  having  been  brought  to  a  red  heat  perhaps  the  first 
day,  stands  for  the  remaining  time  immersed  in  this  red-hot  bath 
of  flame.  When  the  time  for  firing  the  furnaces  has  expired  they 
are  suffered  to  cool  off  slowly,  and  in  a  day  and  a  half  the  boxes 
are  removed  from  the  ovens  and  dumped  on  the  large  cast-iron 
floor.  This  floor  is  a  necessary  part  of  the  plant.  When  it  is 
used  for  oxidizing  the  turning-chips  it  is  heated  by  the  hotair 
from  the  furnaces,  which  may  be  caused  to  pass  underneath  it  on 
their  way  to  the  chimney.  It  is  not  heated  when  the  contents  of 
the  boxes  are  emptied  upon  it,  and  when  these  are  cool  enough  to 
handle  the  iron  turnings  which  have  become  caked  upon  them 
quite  strongly  are  knocked  off  and  the  pieces  are  carried  to  the 
tumbling  barrels,  where  they  are  rattled  until  bright. 

The  cast-iron  articles  subjected  to  the  above  process  have  a  mal¬ 
leable  skin  only ;  the  depth  of  this  is  determined  by  the  thorough¬ 
ness  of  the  process,  and  the  core  or  body  of  the  material  beneath 
this  is  still  brittle.  For  this  reason  screws  made  from  it  having 
threads  cut  through  the  skin  are  deficient  in  strength.  The  skin  is 
as  refractory  to  melt  as  wrought-iron,  but  if  this  skin  is  broken  and 
the  piece  heated  to  a  white  heat  the  inside  will  either  run  out  of 
the  rupture  in  a  fluid  state  or,  if  it  does  not  flux,  it  will  shake  out 
like  sand.  In  this  way  articles  of  intricate  shapes  may  be  made 
light  of  weight  by  pouring  out  the  fluid  interior  and  leaving  the 
harder  outer  shell. 

Th«  chemical  change  in  the  iron  which  the  annealing  produces 
is  so  great  that  the  boxes  used  to  anneal  in,  and  which  are  so  long 
exposed  to  heat,  will  last  four  or  five  times  as  long  if  cast  from 
malleable  scrap  than  they  will  if  cast  from  pig-iron.  For  melting 


MISCELLANEOUS. 


479 


pots  for  the  more  fusible  metals  and  alloys,  such  as  lead,  tin  or 
babbitt,  this  metal  is  far  preferable  to  common  iron.  It  is  also  of 
great  value  for  making  cast-iron  gas  retorts,  which  are  still  in  use 
to  some  extent,  though  generally  superseded  by  fire-brick  in  gas¬ 
works.  It  is  excellent  for  use  in  making  any  articles  that  are  to  be 
exposed  to  continuous  heat,  as  pipe,  in  connection  with  furnaces. 

Lead  Lapping. — This  process  consists  of  grinding  work  in  a  lathe 
by  means  of  emery  powder,  oil  being  mixed  with  the  emery  to 
hold  it  in  place  and  render  its  application  possible.  A  lap  is  a 
mandril  used  to  grind  holes  which  are  not  quite  true,  or  are  too 
small,  or  have  been  hardened  and  cannot  be  cut  by  a  tool.  A  lap 
may  be  a  piece  of  copper  rod,  or  of  iron,  with  a  tin  or  lead  coat 
around  it.  The  diameter  of  a  lap  should  be  turned  to  an  easy  fit, 
at  both  ends  in  the  hole,  and  a  trifle  larger  in  the  middle,  so  that 
the  hole  which  it  is  intended  to  grind  will  fit  tightly  on  the  man¬ 
dril,  the  lathe  being  three  times  the  length  of  the  former. 

Put  the  lap  in  the  lathe  and  through  the  hole  to  be  ground,  run 
the  lathe  at  high  speed,  and  apply  oil  and  emery,  moving  the  work 
back  and  forth  until  it  will  pass  easily  over  the  large  part  of  the 
lap ;  then  stop  the  lathe  and  hack  the  lathe  with  a  cold-chisel,  put 
on  more  oil  and  emery,  and  grind  as  before.  Care  should  be  taken 
that  the  work  is  rotated,  in  order  that  all  sides  of  the  hole  grind 
evenly.  For  holes  to  be  made  true,  smooth  and  parallel,  the  work 
is  bored  as  well  as  possible,  then  set  upon  a  true  surface  like  a 
planer  table,  and  the  lap  applied.  The  mandril  should  be  very 
long  and  tapered,  and  for  hard  lapping  the  extreme  end  of  the  man¬ 
dril  should  be  fitted  to  a  bearing,  bolted  to  the  planer  table,  and 
the  office  of  this  bearing  is  to  prevent  all  erratic  movements  of  the 
mandril  while  grinding.  The  process  is  the  same  as  for  hard  lap¬ 
ping,  except  the  work  is  moved  by  power.  Care  must  be  taken 
that  the  lap  does  not  become  dry  during  the  process.  If  it  does  there 
is  apt  to  be  heating  and  destruction  of  the  lap-surface,  even  if  no 
harm  comes  to  the  object  being  finished. 

Lead  lapping  is  resorted  to  when  great  accuracy  of  surface  is  de¬ 
sired,  as  well  as  high  polish,  and  where  a  finish  by  filing  and  an 


480 


THE  METAL  WORKER’S  HANDY-BOOK. 


application  of  emery  paper  would  not  do,  although  the  method  is 
sufficient  for  rough  work  and  small  journal  bearings. 

Figs.  56  and  57  show  a  form  of  lap.  It  is  a  cast-iron  cylinder, 
or  sleeve,  split  nearly  in  two,  as  shown,  and  fitted  with  lugs  and  a 
thumb-screw  to  admit  of  changing  the  size  of  the  sleeve.  It  will 
be  noticed  that  the  cast-iron  sleeve  comes  entirely  together  at  a, 
and  the  size  of  the  object  to  be  ground  is  determined  by  this  stop. 
If  the  lap  becomes  too  much  worn,  a  little  metal  may  be  filed  from 
the  surface  which  comes  in  contact.  The  interior  of  the  cylinder  is 


brushed  with  lead  and  charged  with  a  flux  of  emery  and  oil,  the 
thumb-screw  is  loosened,  and  the  lap  applied  to  the  object  to  be 
ground,  when  it  is  running  in  the  lathe  at  a  speed  of  300  lineal 
feet  per  minute. 

For  some  work  the  cast-iron  cylinder  may  be  made  with  a  hinge 
opposite  the  thumb-screw,  giving  ready  access  to  the  interior  of 
the  lap. 

Fig.  59  is  an  internal  lap.  It  is  simply  a  piece  of  lead,  cast  in 
the  taper  arbor,  which  is  fluted  to  prevent  the  lead  from  revolving 
upon  it.  The  lead  is  turned  to  size  and  charged  with  emery  and 
oil.  The  size  is  maintained  by  driving  the  taper  arbor  further 
through  the  lead,  which,  being  forced  out  by  the  round  arbor,  ex- 


MISCELLANEOUS. 


481 


pands  in  every  direction,  and  thus  keeps  its  shape.  Fig.  58  shows 
an  end  view  of  the  arbor  and  the  lead  tap  upon  it. 

A  cheap  lap  for  coarse  work  is  shown  at  Fig.  60.  It  consists  of 
two  pieces  of  pine  wood,  cut  out  as  shown,  to  receive  the  shafts, 
and  a  leather  hinge  to  connect  the  parts.  To  polish  a  shaft,  open 
the  clamp,  daub  oil  and  emery  in  the  notches  and  close  the  lap 
upon  the  work.  Fig.  61  shows  a  more  accurate  form  of  the  variety 
of  lap.  The  pieces  are  made  of  cast-iron  and  brushed  with  lead, 
then  reamed,  as  already  described.  The  set-screws  shown  on  top 
of  this  lap  determine  the  size  of  the  hole  to  fit  the  work,  and 
the  bottom  screws  clamp  the  lap  firmly  against  the  set-screws. 
(James.  F.  Hobart.) 

Sawing  Iron  and  Steel '.* — In  a  machine  shop  there  is  a  constant 
demand  for  means  to  cut  off  or  to  nick  pieces  of  iron  and  steel  that 
cannot  readily  be  put  into  the  lathe  on  centres.  The  nicking  saw 
is  the  usual  method  employed,  the  saw  being  driven  on  centre  by  a 
dog,  as  a  shaft  would  be  termed,  and  the  work  to  be  sawed  fed  to 
it  by  the  cross  feed  or  other  means.  To  make  these  nicking  saws 
and  to  properly  temper  them  tries  the  patience  of  the  mechanic 
that  does  not  understand  the  “know-how.”  It  is  simple.  First, 
do  not  turn  or  face  up  a  nicking  saw.  Cut  it  out  of  sheet  cast- 
steel  without  a  particle  of  forging,  selecting  the  steel  of  the  proper 
thickness.  During  all  the  process  of  making  do  not  disturb  the 
“skin  ”  of  the  steel  formed  by  the  rolls  under  which  it  was  made, 
either  by  filing,  smithing  or  polishing.  Cut  the  disk  out  with  a 
cold-chisel  and  file  it  to  circle ;  file  the  teeth  like  those  of  the 
straight  iron  saw — those  of  the  common  “buck-saw”  for  wood 
sawyers  are  a  pattern — and  make  no  set  on  them.  Iron  saws  re¬ 
quire  to  make  no  kerf.  The  teeth  need  not  project  on  either  side. 
Of  course,  the  saws  must  be  drilled  for  a  mandril,  which  should  be 
of  steel,  before  they  are  toothed,  being  turned  true  on  the  mandril, 
to  which  they  should  be  secured  by  check-pin  and  nut.  It  is 
economy  to  make  a  dozen  or  even  more  at  a  time.  Drill  the  man¬ 
dril  hole  and  the  notch  in  the  hole  for  the  check-pin,  or  “  steady- 
pin  ”  as  some  call  it,  turn  them  as  a  whole,  and  cut  the  teeth  all 
*  Jesse  H.  Lord,  in  Manufactured  s  Gazette. 


31 


482 


THE  METAL  WORKER’S  HANDY-BOOK. 


together  in  a  slabber  or  milling  machine.  All  this  without  smith¬ 
ing  or  facing  up  in  the  lathe,  preserving  the  steel-face  intact. 

The  sizes  of  these  saws  for  ordinary  shop  use  are  confined,  for 
efficient  practice,  to  a  diameter  of  3  inches,  or  at  most  3^  inches, 
ranging  downward,  until  for  some  work,  diameters  of  1  inch, 
cutting  not  more  than  ^  inch  under  the  mandril  are  necessary. 

To  temper  these  saws  is  the  great  trouble  with  many  workmen. 
The  saws  vary  in  thickness  from  y& -inch  to  y^-inch  and  in  diameter 
from  3  inches  to  inches,  sometimes  exceeding  the  higher  size 
and  sometimes  being  less  than  the  lower  size  mentioned. 

Each  saw  must  be  separately  hardened  and  tempered.  To  do 
this  properly  the  saw  should  be  put  upon  a  rod,  with  nut  to  hold  it 
in  place,  and  heated  over  or  in  a  charcoal  fire,  or  over  one  of  well- 
coked  sea  coal,  to  a  good  red  heat  and  plunged,  slantwise,  in  cold 
water,  and  moved  about  until  cool.  To  temper  the  saw,  smear  it 
when  dry  with  animal  oil — not  kerosene,  but  sperm  or  lard  oil — and 
hold  it  over  the  fire  until  the  oil  takes  fire  and  flashes  in  flame  over 
the  surface  of  the  saw.  Let  the  oil  burn  a  moment  and  then 
quench  it  again.  If  the  saw  is  sprung  it  may  be  straightened  by 
the  hammer  on  the  anvil,  by  fair  blows,  without  danger  of  breaking. 
Some  prefer  to  draw  the  temper  by  heating  a  bar  of  iron  of  about 
the  size  of  the  centre  hole  in  the  saw,  and  putting  the  saw  on  it  so 
that  the  heat  will  work  gradually  out  to  the  circumference,  when 
the  temper  will  be  determined  by  color,  usually  a  straw.  If,  how¬ 
ever,  color  drawing  is  preferred,  a  better  way  is  to  draw  in  a  pan 
of  heated  sand,  clean  and  without  salt,  as  beach  sand  gives  off  fumes 
that  discolor  the  steel  and  mislead  the  eye.  The  oil  test  will  be 
found  the  best. 

The  speed  at  which  these  saws  should  be  run  depends  somewhat 
on  the  material  to  be  cut,  brass  and  other  soft  metals  allowing  a 
quicker  speed  than  iron  and  soft  steel.  About  100  revolutions  per 
minute  will  do  for  three-inch  saws,  giving  about  75  feet  of  circum¬ 
ferential  motion  ;  but  as  the  nicking  saw  is  only  a  thin  mill,  the 
speed  of  the  mill  in  a  milling  machine  is  a  good  guide. 

It  may  be  necessary,  sometimes,  to  cut  off  a  piece  of  hardened 
steel.  This  may  be  done  by  an  untoothed  disk  of  muntz  metal,  or 


MISCELLANEOUS. 


483 


of  hard-rolled  sheet  brass,  fed  with  quartz  sand  and  water,  or  by 
kerosene  oil  and  emery.  In  this  case  it  is  the  sand  or  emery  that 
does  the  cutting,  the  disk’s  edge  merely  presenting  the  abrading 
material  to  the  work.  The  sand  and  water,  or  the  emery  and  oil 
are  handily  fed  through  a  common  funnel  suspended  over  the 
work,  the  amount  being  regulated  by  a  stick  placed  in  the  funnel 
spout. 

Utilization  of  Red-brass  Turnings. — Turnings  from  red-brass 
works  are  frequently  sold  for  a  low  price,  even  by  establishments 
having  facilities  for  casting  in  crucibles,  because  they  are 
apparently  not  fit  for  casting.  These  turnings  can,  however, 
be  profitably  utilized  for  new  castings  as  well  as  an  addition  to 
other  charges.  The  process  is  as  follows  :  The  turnings  are  melted 
by  themselves  and  during  the  melting  process  mixed  with  manganic 
oxide  in  the  proportion  of  5  parts  by  weight  of  manganese  to  100 
of  turnings.  In  charging  for  melting,  it  is  advisable  to  cover  the 
bottom  of  the  graphite  crucible  0.39-inch  deep  with  manganic 
oxide;  upon  this  is  placed  a  layer  of  turnings  about  1.18  inches 
deep,  and  so  on  until  the  crucible  is  full.  During  melting  the  im¬ 
purities  contained  in  the  turnings  settle  on  the  surface  and  can  be 
readily  removed  with  a  graphite  ladle.  The  melt  is  best  cast  in 
buttons  (square  pieces).  When  cool  each  button  is  cut,  in  order  to 
determine  the  qualities  of  the  metal  by  the  fractured  surfaces.  The 
metal  melted  in  this  manner  shows  a  reddish,  nearly  coppery 
fracture,  and  is  very  tenacious  and  dense.  An  addition  of  manganic 
oxide,  not  exceeding,  however,  2 per  cent.,  to  new  material  for 
melting  is  also  recommended.  With  this  method  the  crucible 
should  not  be  covered  with  tallow,  fat,  pitch,  etc.  Boxes  for 
rapidly-running  parts  of  machines  showed  great  durability,  being 
but  little  worn  after  years  of  use. 

Recovery  of  Copper. — In  works  where  great  quantities  of  copper 
are  operated  upon,  it  is  advantageous  to  recover  the  metal  dis¬ 
solved  in  the  cleansing  baths,  which  are  allowed  by  the  major¬ 
ity  of  gilders,  silver  electro-platers  and  galvanoplastic  operators  to 
go  to  waste  with  the  rinsing  water.  The  recovery  of  such  copper 
is  an  easy  and  inexpensive  process.  All  the  liquids  holding  copper 


484 


THE  METAL  WORK  EL’S  1 1  ANDY-BOOK. 


are  collected  in  a  large  cask  filled  with  wrought-  or  cast-iron  scraps. 
By  the  contact  of  the  copper  solution  with  the  iron  a  chemical  re¬ 
action  immediately  takes  place,  by  which  the  iron  is  substituted  for 
the  copper  to  make  a  soluble  salt,  while  the  copper  falls  to  the 
bottom  of  the  cask  as  a  brown  powder.  The  cask  should  be 
sufficiently  large  to  hold  all  the  liquids  employed  in  a  day’s  work. 
The  liquids  are  decanted  every  morning.  The  old  iron  scrap  is 
generally  suspended  in  a  willow  basket  near  the  top  of  the  liquid, 
and,  by  occasionally  moving  it  about  in  the  liquid,  the  metallic 
powder  of  copper  alone  falls  to  the  bottom  of  the  cask. 

The  same  method  is  employed  for  recovering  the  copper  from 
old  cleansing  acids  or  from  spent  galvanoplastic  baths.  The  cop¬ 
per  thus  obtained  is  quite  pure,  and,  by  calcining  it  in  contact 
with  the  air,  a  black  oxide  of  copper  is  obtained,  which  is  serviceable 
for  enriching  and  neutralizing  galvanoplastic  baths  too  strongly 
acidified. 

Recovery  of  Gold  frotn  Gold  Baths,  etc. — To  recover  the  gold 
from  old  cyanide  gilding  baths,  evaporate  the  baths  to  dryness, 
mix  the  residue  with  litharge  and  fuse  the  mixture.  The  gold  is 
contained  in  the  lead  button  thus  obtained.  The  latter  is  then 
dissolved  in  nitric  acid,  whereby  the  gold  remains  behind  in  the 
form  of  insoluble  spangles.  These  spangles  are  filtered  off  and 
dissolved  in  aqua  regia. 

The  following  method  is  used  for  the  recovery  of  the  gold  by  the 
wet  process:  The  bath  containing  gold,  silver  and  copper  is 
acidulated  with  hydrochloric  acid,  which  causes  a  disengagement 
of  hydrocyanic  acid.  This  gas  is  extremely  poisonous,  for  which 
reason  the  operation  should  be  carried  on  in  the  open  air,  or  where 
there  is  a  good  draft  or  ventilation  to  carry  off  the  fumes.  A  pre¬ 
cipitate  consisting  of  the  cyanides  of  gold  and  copper,  and  chloride 
of  silver,  is  formed.  This  is  well  washed  and  boiled  in  aqua  regia, 
which  dissolves  the  gold  and  copper  as  chlorides,  leaving  the 
chloride  of  silver  behind.  The  solution  containing  the  gold  and 
copper  is  evaporated  nearly  to  dryness,  in  order  to  remove  the  ex¬ 
cess  of  acid,  the  residue  is  dissolved  in  a  small  quantity  of  water, 
and  the  gold  precipitated  therefrom  as  a  brown  metallic  powder, 


MISCELLANEOUS. 


4S5 


by  the  addition  of  sulphate  of  iron  (copperas).  The  copper  re¬ 
mains  in  solution. 

Recovery  of  Gold  and  Silver  from  Sweepings  and  other  Refuse 
from  the  Manufacture  of  Gold-ware ,  etc. — Collect  the  sweepings, 
dry  them,  if  necessary,  and  heat  them  in  a  Hessian  crucible,  in 
order  to  destroy  all  the  organic  substances.  Triturate  the  glowed 
mass  in  a  porcelain  dish  or  enamelled  kettle  with  water,  and  treat 
it  with  an  excess  of  hydrochloric  acid  to  dissolve  any  alkalies  or 
calcium  carbonate  present.  The  portion  remaining  undissolved 
contains  gold,  silver,  copper,  sand,  clay,  ferric  oxide,  etc.  To 
recover  the  silver  from  it  wash  it  thoroughly  with  distilled  water 
and  boil  it  in  pure  nitric  acid,  which  absorbs  the  silver.  The 
residue  is  again  thoroughly  washed,  and  from  the  combined  fluids 
the  silver  is  precipitated  as  chloride  of  silver  by  common  salt,  or, 
still  better,  by  hydrochloric  acid.  The  residue  remaining  midis- 
solved  after  the  treatment  with  hydrochloric  acid  is  heated  with 
aqua  regia  and  the  gold  precipitated  by  the  addition  of  sulphate 
of  iron  (copperas).  Sometimes  it  may  pay  to  treat  the  residue  re¬ 
maining  undissolved  in  aqua  regia  with  ammonia  in  order  to  ex¬ 
tract  the  .chloride  of  silver,  the  formation  of  which  under  the 
given  conditions  can  scarcely  be  prevented.  An  experiment  with  a 
small  portion  will  show  whether  such  treatment  is  advisable  or 
not. 

Ungilding. — Gilded  articles  of  iron  and  steel  are  best  ungilded 
by  treating  them  as  the  anode  in  a  solution  of  from  2  to  2^  ozs. 
of  98  per  cent,  potassium  cyanide  in  1  quart  of  water,  and  suspend¬ 
ing  a  copper  plate  greased  with  oil  or  tallow  as  the  cathode. 
Gilded  silver-ware  is  readily  ungilded  by  heating  it  to  glowing 
and  then  immersing  it  in  dilute  sulphuric  acid,  whereby  the 
layer  of  gold  cracks  off,  the  glowing  and  immersing  in  dilute  sul¬ 
phuric  acid  being  repeated  until  all  the  gold  is  removed.  Before 
glowing  and  immersing  in  dilute  sulphuric  acid  the  articles  may 
first  be  provided  with  a  coating  of  a  paste  of  sal-ammoniac,  flowers 
of  sulphur,  borax  and  potassium  nitrate,  which  is  allowed  to  dry. 
On  the  bottom  of  the  vessel  containing  the  dilute  sulphuric  acid 
the  gold  will  be  found  in  the  form  of  laminae  and  scales.  These 


THE  METAL  WORKER'S  HANT)Y-BOOK. 


4  SO 

are  boiled  with  pure  sulphuric  acid,  washed,  and  finally  dis¬ 
solved  in  aqua  regia  and  made  into  chloride  of  gold  or  fulminating 
gold. 

To  ungild  articles  of  silver,  copper  or  German  silver,  which  will 
not  bear  glowing,  the  solution  of  the  gold  may  be  effected  in  a 
mixture  of  i  lb.  of  fuming  sulphuric  acid,  2.64  ozs.  of  concentrated 
hydrochloric  acid  and  1.3  ozs.  of  nitric  acid  of  40°  B6.  Dip  the 
articles  in  this  warm  acid  mixture,  and  observe  the  progressive 
action  of  the  mixture  by  frequently  removing  the  articles  from  it. 
The  articles  to  be  treated  must  be  perfectly  dry  before  dipping 
them  in  the  mixture,  and  care  must  be  had  to  preserve  the  latter 
from  dilution  with  water  in  order  to  prevent  the  acids  from  acting 
upon  the  base-metals. 

Utilization  of  Nickel  Waste.- — For  the  utilization  of  waste  from 
rolled  and  cast-nickel  anodes  and  of  the  nickel  sand  gradually  col¬ 
lecting  upon  the  bottom  of  the  vats,  the  following  method  is 
recommended  :  Wash  the  waste  repeatedly  in  clean  hot  water,  and 
then  boil  in  dilute  sulphuric  acid  (1  part  acid  to  4  water)  until 
water  poured  upon  the  waste  is  no  longer  clouded  by  it.  Then 
pour  off  the  liquid  and  treat  the  waste  or  sand  with  concentrated 
nitric  acid.  This  must  be  done  very  carefully,  and  a  large  porcelain 
vessel  should  be  used  to  prevent  the  solution  from  running  over. 
When  the  solution  is  sufficiently  concentrated,  so  that  it  contains 
little  free  acid,  it  should  be  filtered  and  slowly  evaporated  to  dry¬ 
ness  over  the  water  bath.  The  product  is  nickel  nitrate.  The 
nickel  nitrate  thus  obtained  is  dissolved  in  hot  distilled  water,  and 
the  solution  precipitated  with  caustic  soda  carefully  and  gradually 
added.  The  precipitate  of  hydrated  nickel  oxide  is  then  carefully 
filtered  and  washed,  then  treated  with  dilute  sulphuric  acid  with 
the  aid  of  heat  until  solution  has  taken  place.  The  solution  is 
concentrated  by  evaporation  and  an  excess  of  concentrated  solu¬ 
tion  of  ammonium  sulphate  is  added.  The  precipitate  is  the 
double  sulphate  of  nickel  and  ammonium,  or  Adams’  nickel-plating 
salt,  which  is  commonly  used  for  nickel-plating. 

To  Recover  Nickel  from  Old  Solutions. —  Urquhart  proposes  the 
following  plan  :  Make  a  saturated  solution  of  ammonium  sulphate 


MISCELLANEOUS. 


4S7 


in  warm  water  and  add  to  it  the  old  nickel-plating  solution,  with 
constant  stirring,  and,  after  the  lapse  of  a  few  minutes,  a  granular 
precipitate  of  the  double  sulphate  of  nickel  will  begin  to  separate. 
The  addition  of  ammonium  sulphate  should  be  from  time  to  time 
continued,  until  the  liquid  is  colorless.  The  precipitated  salt  is 
very  pure,  and  may  be  used  directly  in  making  a  new  bath. 

Recovery  of  Silver  from  Old  Cyanide  Plating  Solutions ,  etc. — The 
baths  may  be  evaporated  to  dryness,  the  residue  mixed  with  a  small 
quantity  of  calcined  soda  and  potassium  cyanide  and  fused  in  a 
crucible,  whereby  metallic  silver  is  formed,  which,  when  the  heat 
is  sufficiently  increased,  will  be  found  as  a  button  upon  the  bottom 
of  the  crucible;  or  if  it  is  not  desirable  to  heat  to  the  melting 
point  of  silver,  the  fritted  mass  is  dissolved  in  hot  water,  and  the 
solution  containing  the  soda  and  cyanide  quickly  filtered  off  from 
the  metallic  silver.  The  evaporation  of  large  quantities  of  fluid  is, 
to  be  sure,  inconvenient,  and  requires  considerable  time,  but  the 
reducing  process  above  described  is  without  doubt  the  most  simple 
and  least  injurious. 

According  to  the  wet  method  the  bath  is  strongly  acidulated  with 
hydrochloric  acid,  observing  the  precaution  to  provide  for  the 
effectual  carrying  off  of  the  hydrocyanic  acid  liberated  as  given 
under  gold.  Remove  the  precipitated  chloride  of  silver  and 
cyanide  of  copper  by  filtration,  and  after  thorough  washing, 
transfer  it  to  a  porcelain  dish  and  treat  it,  with  the  aid  of  heat, 
with  hot  hydrochloric  acid,  which  will  dissolve  the  cyanide  of  cop¬ 
per.  The  resulting  chloride  of  silver  is  then  reduced  to  the 
metallic  state  by  mixing  it  with  four  times  its  weight  of  crystallized 
carbonate  of  sodium  and  half  its  weight  of  pulverized  charcoal. 
The  whole  is  made  into  a  homogeneous  paste,  which  is  thoroughly 
dried,  and  then  introduced  into  a  strongly  heated  crucible.  When 
all  the  material  has  been  introduced  the  heat  is  raised  to  promote 
complete  fusion  and  to  facilitate  the  collection  of  the  separate 
globules  of  silver  into  a  single  button  at  the  bottom  of  the  crucible, 
where  it  will  be  found  after  cooling. 

If  granulated  silver  is  wanted,  pour  the  metal  in  a  thin  stream, 
and  from  a  certain  height,  into  a  large  volume  of  water. 


4SS  TITE  METAL  WORKER’S  HANDY-BOOK. 

Desilvering. — According  to  the  nature  of  the  base-metal  different 
methods  have  to  be  employed  for  desilvering.  Silvered  iron 
articles  are  treated  as  anode  in  a  potassium  cyanide  solution  in 
water  (1:20),  the  iron  not  being  brought  into  solution  by  potassium 
cyanide ;  as  cathode  suspend  in  the  solution  a  few  silver  anodes  or  a 
copper-sheet  rubbed  with  an  oily  rag.  The  silver  precipitates  upon 
the  copper-sheet,  but  does  not  adhere  to  it.  Articles,  the  basis  of 
which  is  copper,  are  best  desilvered  by  immersion  in  a  mixture  of 
equal  parts  of  anhydrous  (fuming)  sulphuric  acid  and  nitric  acid 
of  40°  Be.  This  mixture  makes  the  copper  passive,  it  not  being 
attacked,  while  the  silver  is  dissolved.  Care  must,  however,  be 
had  not  to  introduce  any  water  into  the  acids,  nor  to  let  them 
stand  without  being  hermetically  closed,  since  by  absorbing  water 
from  the  air  they  become  dilute,  and  may  then  exert  a  dissolving 
effect  upon  the  copper.  The  fuming  hydrochloric  acid  may  also 
be  heated  and  150  parts  of  crystallized  nitrate  of  soda  be  added 
instead  of  the  nitric  acid.  In  this  hot  acid  desilvering  proceeds 
more  quickly  than  in  the  cold  acid  mixture,  but  the  latter  acts  more 
uniformly.  Desilvering  is  complete  when  the  articles,  on  being 
pickled,  show  no  stains. 

Recovery  of  Platinum  from  Platinum  Solutions. — From  not  too 
large  baths  precipitation  of  the  platinum  with  sulphuretted  hydrogen 
is  the  most  suitable  method,  and  preferable  to  evaporating  and  re¬ 
ducing  the  metal  from  the  residue.  The  process  is  as  follows : 
Acidulate  the  platinum  solution  with  hydrochloric  acid,  and,  after 
warming  it,  conduct  sulphuretted  hydrogen  into  it.  The  metal 
(together  with  any  copper  present)  precipitates  as  sulphide  of 
platinum.  The  precipitate  is  filtered  off,  dried  and  glowed  in  the 
air,  whereby  metallic  platinum  remains  behind.  From  larger  baths 
the  platinum  may  be  precipitated  by  suspending  bright  sheets  of 
iron  in  the  acidulated  bath.  In  both  cases  the  precipitated  plati¬ 
num  is  treated  with  dilute  nitric  acid  in  order  to  dissolve  any  cop¬ 
per  present.  After  filtering  off  and  washing  the  pure  platinum  it 
is  dissolved  in  aqua  regia ;  the  solution  is  then  evaporated  to  dry¬ 
ness  in  the  water  bath,  and  the  chloride  of  platinum  thus  obtained 
may  be  used  in  making  a  new  bath. 


MISCELLANEOUS. 


489 


Recovery  of  Tin  from  Tin-plate  Waste. — The  waste  is  treated  with 
dilute  chlorine  at  a  temperature  above  the  boiling  point  of  chloride 
of  tin,  so  that  the  latter  immediately  after  its  formation  is  carried 
away  in  the  form  of  vapor,  as,  if  it  remains  in  the  form  of  a  fluid 
in  contact  with  the  residues,  it  gives  rise  to  the  formation  of  chloride 
of  iron,  chloride  of  tin  being  reduced.  The  vapors  of  chloride 
of  tin  are  precipitated  by  steam  or  by  contact  with  moist  surfaces 
in  roomy  condensing  chambers,  or  are  absorbed  by  chloride  of  tin 
solution  of  medium  concentration. 

Another  method  is  as  follows  :  Bring  the  waste  into  contact  with 
sulphur  in  a  boiling-hot  solution  of  sodium  sulphide,  whereby  the 
iron  is  completely  freed  from  tin.  The  waste  thus  freed  from  tin 
is  thoroughly  washed  and  dried,  heated  to  a  welding  heat  in  tubes 
of  rolled-iron,  taken  out  and  hammered  into  rod-iron.  The  solu¬ 
tion  of  sodium  sulphide  holding  the  tin  is  evaporated,  the  residue 
calcined  in  a  reverberatory  furnace  and  the  calcined  mass  reduced 
to  tin,  at  a  raised  heat,  by  means  of  a  mixture  of  small  coal,  char¬ 
coal  and  calcined  soda  or  burnt  lime. 

To  Separate  Lead  from  Zinc. — Melt  the  alloy.  The  specifically 
heavier  lead  collects  in  the  lower  portion  of  the  crucible,  while  the 
lighter  zinc  stands  above  it  and  can  be  poured  off. 

How  fapanese  Swords  are  Made. — In  forging  the  metal  is  never 
heated  without  being  carefully  coated  with  loam  spread  all  over  it 
as  a  thin  wash  and  sprinkled  with  straw  ashes.  The  metal,  too,  is 
kept  perfectly  clean,  and  never  touched  by  the  hand,  as  the  least 
sweat  will  hinder  the  perfectly  uniform  welding  of  the  parts  together 
and  leave  a  flaw  visible  in  the  sword.  A  steel  plate  with  an  iron 
rod  welded  to  it  as  a  handle,  and  with  several  pieces  of  steel  placed 
upon  it,  is  heated  in  the  fire,  and  is  hammered  out  on  the  anvil  to  a 
shape  about  6  or  8  inches  long  by  inches  wide  and  %  or 
inch  thick.  The  steel  bar  so  forged  is  doubled  over,  heated  again 
and  hammered  out  into  about  the  same  dimensions  as  before ; 
doubled  over  again,  reheated  and  hammered  until  it  has  been 
refolded  fifteen  times.  Then  its  handle  is  cut  off,  and  in  like  man¬ 
ner  three  such  bars  are  made  and  the  four  bars  welded  into  a  some¬ 
what  longer  bar,  and  thus  again  folded  and  hammered  out  to  about 


490 


THE  METAL  WORKER’S  II ANDY-BOOK. 


the  same  dimensions.  The  resulting  bar  is  made  up  of  a  vast 
number  of  layers  intimately  welded  together.  The  first  doubling 
gives  2,  the  second  4,  and  so  on  up  to  the  fifteenth,  which  gives 
32,768,  and  the  four  small  bars  together  consist  of  131,072  layers, 
and  after  15  additional  foldings  there  must  be  4,194,304  layers. 
In  consequence,  the  polished  sword  lias  fine  lines  like  the  grain  of 
wood.  They  are  called  the  sword’s  hada  (skin),  and  are  distinguished 
by  names  according  to  their  form.  The  steel  bar  is  now  hammered 
out  to  the  length  of  the  required  blade,  and  after  various  manipula¬ 
tions  is  given  its  shape,  apparently  without  measurements  or  pat¬ 
terns.  When  iron  is  used  along  with  the  steel  there  are  several 
ways  of  combining  the  small  bars  to  make  the  large  one,  the 
smiths  of  different  provinces  using  different  methods.  In  harden¬ 
ing,  the  blade  is  covered  with  a  coating  of  loam,  which  is  carefully 
removed  along  the  edge,  and  is  then  heated  in  a  vigorous  fire  of  pine 
charcoal.  Afterwards  it  is  cooled  by  dipping  in  lukewarm  water. 
The  blade  is  then  carefully  cleaned  and  examined  for  blemishes. 
A  smith  careful  of  his  reputation  rejects  all  imperfect  blade6  and 
uses  the  material  for  other  purposes.  Next  the  smith  cuts  the 
groove,  if  any,  with  a  steel  graving  tool.  These  grooves  lighten 
the  sword,  and  are  called  vulgarly  chi-nagashi  (blood  chains).  The 
smith  then  drills  the  hole  in  the  tong  for  the  bamboo  or  metallic 
peg  that  holds  the  handle  on. 

Many  smiths  adorn  their  blades  with  engravings,  especially  with 
representations  of  dragons,  gods,  and  flower  sprigs. 

The  final  grinding  and  polishing  is  a  trade  quite  distinct  from 
the  smith’s.  The  grinder  holds  the  sword  horizontally,  and  rubs  it 
back  and  forth  on  a  small  whetstone  well  wet  with  water,  moving  by 
degrees  along  the  whole  length  of  the  blade.  Finally  the  blade  is 
polished  with  a  polishing  stone  and  a  stone  powder  as  fine  as  flour, 
or  with  the  finest  powdered  steel  forge  cinders  until  the  polish  is 
perfect. 

The  blade  may  now  be  mounted  with  a  hilt,  and,  if  moderately 
long,  with  a  guard,  with  a  ferrule  and  a  scabbard.  The  hilt  is  made 
of  wood  often  covered  with  shark’s  skin,  the  rougher  the  better. 
Over  the  shark’s  skin  silk  cord  is  often  found  crosswise  in  several 


MISCELLANEOUS. 


491 


styles.  Between  the  shark’s  skin  and  the  cord  there  is  often  a 
metallic  ornament.  The  guard  is  only  put  on  the  larger  swords, 
and  is  preferably  made  of  steel  or  the  hardest  wrought-iron.  It  is 
sometimes  a  work  of  fine  art,  and  .then  often  has  the  maker’s  name 
engraved  upon  the  concealed  part  of  it. 

To  Make  Knives  from  Old  Files. — First  draw  the  temper  by 
heating  the  file  to  a  cherry-red,  then  place  it  in  ashes,  and  5  inches 
under  the  forge,  and  leave  it  there  until  cool.  Now  grind  out  the 
file  marks  and  next  comes  the  drawing.  Make  the  heat  no  higher 
than  a  bright  cherry  heat,  and  use  a  good  smooth-faced  hammer. 
The  file  is  then  drawn  a  little  thicker  than  the  back  of  the  blade  is 
to  be,  and  the  blade  is  then  bent,  the  edge  being  on  the  inside.  The 
blade  is  then  drawn  to  an  edge,  the  drawing  on  the  inner  curve 
having  the  effect  of  straightening  it.  When  it  has  been  drawn  to 
an  even  and  nice  color  and  straightened,  three  holes  are  drilled  in 
it  so  that  the  handle  can  be  fastened  on  it,  and  it  is  shaped  with  a 
file.  It  is  necessary  to  avoid  getting  the  edge  too  thin,  or  else  there 
will  be  trouble  in  tempering.  In  tempering  use  soft  and  some¬ 
what  warm  water.  Seize  the  handle  ends  with  a  pair  of  tongs,  hold 
the  blade,  with  the  back  down,  over  a  clear,  well-charred  fire,  and 
heat  evenly  to  the  first  hole  until  the  blade  is  red,  and  then  plunge 
it  endwise  into  the  water.  This  should  leave  the  blade  so  that 
when  tried  with  a  file  the  file  will  take  hold,  just  a  little.  If  this 
test  shows  that  the  blade  is  too  hard,  dip  it  in  linseed  oil,  hold  it 
over  a  slow,  clear  fire  until  the  oil  ignites,  and  then  dip  into  the 
water  again.  This  will  toughen  it,  and  cause  it  to  hold  its  edge 
better.  The  grinding  should  be  done  on  a  good  even-faced  stone. 

Ma7iufaclure  of  Metal  Pipes. — The  following  process,  the  inven¬ 
tion  of  F.  Madeley,  is  patented  in  England  :  A  piece  of  soft  steel 
is  in  a  suitable  manner  bent  to  a  pipe  so  that  both  edges  lie  close 
together  It  is  then  polished  and  coated  with  copper  in  a  suitable 
cyanide  solution.  For  a  layer  of  copper  of  special  thickness  it  is 
further  treated  in  a  solution  of  cupric  sulphate.  The  pipe  is  then 
further  coated  with  brass  in  a  suitable  cyanide  solution  and  finally 
polished.  In  this  manner  pipes  with  a  metallic  coating  are  obtained 
without  the  necessity  of  soldering  or  welding. 


402 


TITE  METAL  WORKER’S  HANDY-BOOK. 


Improvement  in  the  Treatment  of  Steel. — C.  Jones,  of  Derby, 
England,  lias  patented  the  following  process :  Steel  scraps  (railway 
carriage  and  other  carriage  springs),  after  being  cleaned  by  immer¬ 
sion  in  dilute  sulphuric  acid  and  subsequent  washing  in  boiling 
water,  are  first  dipped  into  oil  or  grease  and  then  into  soot.  The 
scraps  are  then  packed  with  powdered  gas  coke  into  a  metal  box 
and  heated  in  a  furnace  for  30  hours  or  more,  at  about  1400°  F., 
then  withdrawn  and  allowed  to  cool  slowly.  The  scrap  may  then 
be  melted  into  blocks  or  ingots,  which  can  be  rolled,  welded,  ham¬ 
mered  or  otherwise  treated  in  the  usual  way. 

Ink  for  Writing  on  Tin. — Dissolve  1  part  of  copper  in  10  of 
nitric  acid,  and  add  to  the  solution  10  of  water.  Cleanse  the  tin 
with  dry  whiting  and  write  with  a  quill. 

Ink  for  Writing  on  Zinc. — Cleanse  the  surface  of  the  zinc  by 
rubbing  with  a  sponge  dipped  in  dilute  hydrochloric  acid  and  fine 
sand.  Next  dissolve  1  oz.  4  drachms  each  of  crystallized  verdigris 
and  sal-ammoniac  in  1  pint  of  warm  water,  filter  the  solution  after 
cooling,  and  preserve  it  in  well-closed  bottles.  Pieces  of  zinc 
written  on  with  this  preparation  are  allowed  to  lie  in  water  a  few 
hours.  They  are  then  dried  and  used  without  being  varnished. 
The  writing  may  be  executed  with  a  steel  pen  or  a  quill,  the  first 
being,  however,  strongly  attacked  by  the  fluid.  In  case  the  zinc 
appears  greasy  and  the  writing  runs  together,  cleanse  the  surface 
with  a  rag  dipped  in  chalk.  This  ink  is  very  suitable  for  writing 
labels. 

Insulating  Coverings  for  Steam-pipes ,  etc. — Felt,  cork,  waste, 
mineral  wool  or  asbestos  pulp,  either  made  into  suitable  forms  and 
atttached  to  the  pipe,  or  filled  into  a  casting  surrounding  the  pipe, 
and  with  or  without  an  air  space  about  the  pipe,  are  much  used  for 
the  above  purpose.  A  mass  highly  recommended  is  prepared  as 
follows:  100  parts  by  weight  of  finely  ground  limestone,  350  of 
finely  ground  coal,  250  of  pulverized  clay,  300  of  fine  ashes  from 
boiler-flues  are  thoroughly  mixed  with  600  of  water  and  10  of  sul 
phuric  acid  of  50°  Be,  and  after  adding  15  of  hair  (hogs’  bristles, 
cow  hair  or  calf  hair)  the  whole  is  made  as  homogeneous  as  possible. 
The  article  to  be  covered  should,  if  possible,  be  previously  heated. 


MISCELLANEOUS. 


493 


The  mass  is  then  gradually  applied  in  separate  layers,  each  about 
y2- inch  thick,  until  a  thickness  of  i y2  to  inches  is  attained. 
The  whole  may  finally  be  painted  any  color  desired. 

Another  Insulating  Material  for  Steam-pipes  is  prepared  as 
follows :  Boil  i  lb.  each  of  rice  flour,  rye  flour,  cows’  hair  and 
treacle  with  150  quarts  of  water,  and  gradually  and  with  constant 
stirring  add  80  lbs.  of  infusorial  earth.  Apply  the  mass  in  several 
layers  to  the  lukewarm  pipes,  so  that  finally  a  layer  somewhat  more 
than  y2 -inch  thick  is  formed. 

Insulating  Mass  for  Steam-boilers,  etc. — Waste  of  cork,  asbestos, 
gypsum  and  cement,  all  finely  ground,  are  shortly  before  use  made 
with  water  into  a  paste  of  the  consistency  of  mortar.  The  result¬ 
ing  mass  is  applied  with  a  trowel  to  the  objects  to  be  insulated.  It 
answers  the  purpose  far  better  than  masses  containing  hair,  glue, 
treacle,  etc.,  as  it  is  not  subject  to  putrefaction  or  fermentation, 
nor  destroyed  by  heat.  It  being  a  very  poor  conductor  of  heat 
the  highest  useful  effect  can  be  attained  ;  it  adheres  well  and  is 
very  durable. 

Insulating  Material  for  Electrical  Conduits. — Mix  66  parts  of 
fine  glass  or  quartz  powder  and  34  of  finely  pulverized  vegetable  or 
mineral  resin.  Add  to  the  mixture  26  parts  of  paraffine,  beeswax 
or  spermaceti,  and  3  parts  of  boiled  or  crude  linseed  oil.  The 
proportions  of  mixture  vary  according  to  circumstances.  If  the 
mass  is  to  be  exposed  to  the  sun  the  admixture  of  wax  must  be 
small,  while  the  reverse  is  the  case  if  the  mass  is  to  be  used  for 
telegraph  lines  under  ground. 

Flexible  Insulating  Mass  for  Electrical  Conduits. — Mineral  wax 
(paraffine,  ozokerite),  1  part ;  wood  tar,  29;  shellac,  32;  and 
asbestos,  flax  or  cotton,  32,  are  mixed  in  a  boiler  at  between  920 
and  2120  F.,  and  constantly  stirred.  For  a  harder  mass  take  less 
wood  tar.  For  the  production  of  a  specially  hard  mass,  the  wax 
may  be  omitted  and  about  24  parts  of  ground  slate,  infusorial 
earth  or  clay  free  from  iron  added,  and  the  quantity  of  asbestos, 
etc.,  decreased. 

Gold-beating. — The  rough  gold  is  put  into  a  stone  crucible, 
melted,  and  poured  into  a  mould,  which  gives  it  the  right  width 


494 


T1IE  METAL  WORKER’S  HANDY-BOOK. 


for  rolling.  One  hundred  dollars’  worth  of  gold  is  generally 
moulded  at  a  time,  the  weight  being  about  5  ounces.  It  is  then 
run  through  the  rollers,  the  pressure  of  which  is  so  great  that  the 
little  bar  of  gold  that  is  1  inch  thick  in  width  and  about  3  inches 
in  length,  after  being  run  through  several  times,  becomes  a  strip 
about  14  yards  in  length  and  about  the  thickness  of  a  hair.  The 
strip  is  then  cut  into  1  inch  squares.  These  squares  are  put  into 
what  is  called  a  cutch.  This  cutch  is  composed  of  180  skins  314 
inches  square.  The  material  that  these  skins  are  made  of  is  an  in¬ 
vention  of  French  origin,  and  is  kept  secret.  Formerly  vellum 
was  used.  A  gold  square  is  placed  between  each  skin,  one  directly 
over  the  other,  until  the  cutch  is  filled.  Two  parchment  bands 
are  put  over  them  in  opposite  directions  to  keep  them  from  shift¬ 
ing.  The  cutch  is  then  beaten  for  15  or  20  minutes  with  a  16- 
pound  hammer.  The  gold  is  then  taken  out  of  the  skins,  quartered 
by  a  skewer,  and  put  into  what  is  called  the  shorter.  The  number 
of  skins  in  a  shoder  is  680.  These  skins  come  from  what  is  called 
the  bung-gut  of  an  ox,  one  animal  furnishing  but  two  skins.  The 
shoder  skins  are  four  inches  square.  The  gold  squares  are  put 
between  the  skins  in  the  same  manner  as  in  the  cutch.  They  are 
then  beaten  for  1  y?,  hours  with  a  10  lb.  hammer,  taken  out,  and  again 
quartered  with  a  piece  of  reed.  They  are  then  put  into  the  mould, 
one  over  the  other  as  before,  until  the  900  skins  which  the  mould 
contains  are  filled.  This  is  beaten  with  a  hammer  weighing  7  lbs. 
for  3  or  4  hours.  The  leaf  is  then  ready  to  be  trimmed  and 
booked.  Before  the  beating  process  the  skins  are  heated  and 
primed  to  prevent  the  leaf  from  sticking.  Heated  presses  are 
used  to  take  the  moisture  from  the  skins.  Each  skin  is  rubbed 
with  a  hare’s  foot,  with  plaster  of  Paris  on  both  sides,  before  beat¬ 
ing.  Each  one  of  the  first  squares  of  gold  beaten  out  makes  25 
leaves,  or  one  book.  The  trimming  of  the  leaves  before  they  are 
put  into  books  is  done  by  a  sled-shaped  machine  called  a  wagon. 
The  trimming  and  booking  are  mostly  done  by  girls.  The  trim¬ 
mings  that  are  left  from  the  leaves  are  scraped  together  and  melted 
over.  A  little  salt  added  makes  it  thoroughly  clean.  The  granite 
block  that  the  beating  is  done  on  is  about  3  feet  in  height,  the  top 


MISCELLANEOUS. 


495 


surface  being  ground  down  perfectly  smooth,  so  as  to  prevent  the 
blows  of  the  hammer  from  cutting  the  under  side  of  the  mould. 

Lining  for  Furnaces. — The  composition  used  for  lining  furnaces 
consists  of  ganister,  or  a  similar  highly  silicious  mass,  and  lime  in 
the  proportion  of  about  90  parts  of  ganister  to  10  of  lime.  The 
limestone  is  burned  and  slaked,  and  after  12  hours  added  to  the 
ganister.  Sufficient  water  for  the  requisite  consistence  is  then 
added  and  the  whole  thoroughly  mixed.  The  furnace  is  then  lined 
with  the  mass  and  the  latter  dried  by  moderate  firing. 

Matrix  Mass  for  the  Reproduction  of  Ale  da  Is,  Coins,  etc. — Under 
the  name  “  isolit  ”  a  mass  is  brought  into  commerce  which  is 
recommended  as  being  especially  suitable  for  matrices  to  be  used 
in  galvano-plasty.  It  consists  of  yellow  ceresin  (purified  ozo¬ 
kerite),  with  6  or  7  per  cent,  of  petroleum  and  4  or  5  per  cent,  of 
sulphur. 

Oil  of 'Mustard  as  a  Lubricator. — For  preventing  the  welding 
together  of  iron  surfaces  upon  which  much  and  rapid  friction  is 
exercised,  such  as  turbine  wheels,  etc.,  ordinary  oil  of  mustard, 
mixed  with  small  quantities  of  petroleum,  fish  oil,  or  other  similar 
fatty  substances  has  been  found  to  answer  the  purpose  in  every 
respect,  and  to  overcome  all  the  difficulties  heretofore  experienced 
with  machinery  where  excessive  friction  disturbs  the  physical 
quality  of  the  metal  used. 

Spinning  of  Metals. — Spinning  in  the  lathe  is  preferably  employed 
for  shaping  articles  which  are  difficult  to  press  or  draw.  The 
principle  of  spinning  consists  in  forcing  by  the  continuous  pressure 
of  a  tool  of  a  simple  shape  a  sheet  of  metal  into  a  revolving  pat¬ 
tern  (chuck)  or  raising  it  over  the  chuck.  In  the  first  case  the 
inner  surface  of  the  chuck  must  correspond  to  the  outer  contours 
of  the  article  to  be  produced,  whilst  in  the  latter  the  chuck  actually 
forms  the  pattern  of  the  work. 

Fig.  62  shows  both  styles  in  cross-section  and  also  the  manner 
of  securing  the  chucks  in  the  lathe.  F F  are  the  chucks  ;  they  are 
made  of  hard  wood,  generally  white  beach.  Upon  metallic  chucks 
the  sheet-metal  would  very  quickly  spin  hard  ;  the  wooden  chucks, 
however,  are  frequently  covered  with  sheet  brass.  The  chucks 


496 


TIIE  METAL  WORKER’S  ITANDY-BOOK. 


must  be  turned  very  smooth,  and  are  provided  on  one  side  with  a 
female  screw,  by  means  of  which  they  are  secured  to  the  front  end 
of  the  mandril  S,  which  is  provided  with  a  worm.  This  end  is 
also  furnished  with  a  female  screw,  in  which  fits  the  so-called  bind¬ 
ing  screw  D.  The  latter  consists  of  a  steel  rod,  provided  on  one 
end  with  a  worm  about  i*4  inches  long  and  on  the  other  with  a 
disk  and  handle.  The  length  of  the  binding  screw  generally  cor¬ 
responds  to  the  longest  article  to  be  turned ;  for  shorter  articles 
various  orbicular  pieces  V  are  inserted  between  the  chuck  and  the 
disk  of  the  binding  screw.  With  the  use  of  the  binding  screw  the 


chuck  as  well  as  the  sheet-metal  to  be  spun  must  be  provided  with 
an  aperture  for  the  binding  screw  to  pass  through.  The  chuck  and 
disk  of  sheet-metal  before  the  commencement  of  spinning  are 
shown  in  I,  Fig.  62. 

The  spinning  is  done  with  tools  of  various  shapes  resembling 
burnishers;  they  have  either  flat,  flat-round,  club-shaped  or  hook" 
like  faces.  Some  of  the  shapes  are  shown  in  Fig.  63.  The  tools 
should  always  be  kept  dull  and  smooth ;  sharp-edged  or  rough 
tools  must  never  be  used.  A  strong  steel  pin  is  inserted  in  the 


MISCELLANEOUS. 


497 


projection  of  the  lathe,  against  which  the  tool  is  pressed  during 
spinning.  The  tool  is  held  in  the  right  hand  and  pressed  in  slow 
strokes  from  the  centre  towards  the  periphery,  progressing  in  a 
horizontal  direction  from  right  to  left,  whilst  the  plate  of  sheet- 
metal  is  made  to  revolve  by  the  mandril ;  the  plate  is  thereby 
forced  to  gradually  fit  itself  to  the  chuck.  What  shape  of  tool  is 
most  suitable  for  each  kind  of  work  has  to  be  learned  by  experience, 
it  being  impossible  to  give  special  instructions  in  regard  to  this. 
It  need  only  be  remarked  that  at  first  flat-round  tools  are  always 
used  even  in  spinning  sharp  edges ;  flat  tools  are  only  employed 
finally. 


Fig-  63. 


As  indicated  in  Fig.  62,  7,  the  sheet  fits  itself  only  gradually  to 
the  chuck,  and  care  must  be  had  that  the  metal  does  not  wrinkle. 
For  this  purpose  an  entirely  flat  tool  is  held  with  the  left  hand 
against  the  under  side  of  the  plate  so  as  to  be  always  opposite  to 
the  spinning  tool.  Without  the  use  of  this  tool  the  sheet-metal 
would  soon  become  wrinkled  ;  but  when  partially  spun  the  use  of  the 
second  tool  may  be  dispensed  with.  All  metals  cannot  be  spun  with 
equal  facility,  copper  spinning  best,  next  zinc,  tombac  and  brass. 
German  silver  and  tin-plate  are  difficult  to  spin.  To  avoid  friction 
between  the  tool  and  metal-plate  both  are  kept  lubricated  with 
tallow  or  soap-water.  In  spinning  the  metals  become  gradually 


498 


THE  METAL  WORKER’S  HANDY-BOOK. 


hard,  zinc,  for  instance,  becoming  so  hard  in  a  short  time  that  for 
articles  of  any  size  it  can  only  be  spun  warm.  Warming  is  effected 
by  holding  a  spirit-lamp  under  the  article.  When  the  articles  have 
become  hard  and  brittle  by  spinning  they  have  to  be  annealed 
before  they  can  be  further  spun.  By  spinning  the  molecules  have 
assumed  an  abnormal  position  and  are  in  a  state  of  tension.  If 
now  the  half-finished  articles  were  directly  heated  they  would 
frequently  become  full  of  cracks.  To  avoid  this  the  tension  is 
relieved  by  pounding  the  article  with  a  wooden  hammer  upon  a 
wooden  support.  The  small  dents  made  thereby  can  readily  be 
removed  in  finishing  the  spinning.  The  articles  are  first  warmed 
by  placing  them  upon  glowing  coals  and  only  covered  with  coals 
when  thoroughly  heated  through.  In  large  establishments  muffle 
furnaces  are  also  used  for  annealing.  German  silver  sheet  cracking 
readily,  great  care  is  required  in  annealing  it. 

For  flat  articles  with  bright  inner  surfaces  the  chuck  shown  in  II, 
Fig.  62,  is  used;  in  this  case  the  plate  of  sheet-metal  A  A  must  be 
somewhat  larger  than  the  chuck.  After  being  placed  upon  the 
chuck  it  is  covered  with  a  round  wooden  plate  V  This  wooden 
plate  has  in  the  centre  a  brass  plate  with  a  conical  depression,  in 
which  sits  the  back-centre  R.  When  the  sliding-puppet  of  the 
lathe  has  been  brought  as  close  as  possible  to  the  chuck,  in  conse¬ 
quence  of  the  friction  the  wooden  plate  and  the  disk  of  sheet- 
metal  are  also  revolved  by  the  revolution  of  the  chuck.  The  pro¬ 
jecting  edge  of  the  disk  of  sheet-metal  is  then  turned  so  far  around 
the  edge  of  the  chuck  that  it  will  hold  the  disk  when  the  wooden 
plate  V  is  removed.  It  is  still  better  to  press  the  edge  of  the  disk 
of  sheet-metal  into  a  groove  in  the  chuck.  By  now  removing  the 
sliding-puppet  and  the  wooden  plate  V,  the  disk  of  sheet-metal  is 
drawn  over  the  hollow  chuck  like  a  drum-head.  With  the  assistance 
of  the  tools  the  sheet-metal  is  now  pressed  against  the  side  of  the 
chuck  by  working  from  the  edge  towards  the  centre.  The  opera¬ 
tion  being  finished,  the  edge  is  cut  off  with  a  tool. 

Articles  which  are  to  be  smooth  inside  and  outside  are  also  spun 
without  binding  screw  upon  chucks  of  the  above  description. 


MISCELLANEOUS. 


499 


They  are  first  spun  over  a  chuck  and  then  brought  into  a  hollow 
chuck. 

For  the  manufacture  of  hollow  articles  of  jewelry  from  gold- 
sheet  which  is  too  thin  for  direct  working,  a  gold  tube  is  frequently 
enveloped  inside  and  outside  with  silver,  then  filled  with  brass  and 
subjected  to  the  required  manipulations.  The  article  being  finished, 
the  brass  core  is  dissolved  in  a  mixture  of  acids  which  does  not 
attack  the  silver,  and  finally  the  outer  layer  of  silver  is  removed 
with  nitric  acid. 

To  Cut  Sheet-brass  by  Chemical  Means. — By  drawing  a  line  with 
solution  of  mercury  salt  upon  a  sheet  of  brass,  the  latter  on  the 
place  where  the  line  is  drawn  immediately  becomes  as  fragile  as 
glass.  The  mercury  salt  is  decomposed  by  the  acid  dissolving  with 
great  rapidity  the  copper  and  the  mercury  combining  with  the  zinc 
to  an  amalgam. 

To  Toughen  Sheet-brass  for  painting  with  oil  paint  the  following 
process,  which  imparts  to  the  sheet  a  moire-like  appearance,  may  be 
recommended.  Place  the  brass  for  12  hours  in  a  pickle  of  con¬ 
centrated  sulphuric  acid,  8  parts  ;  concentrated  hydrochloric  acid, 
1  ;  and  water,  8 ;  then  rinse  off  with  water.  This  graining  may 
be  hastened  by  using  a  mixture  of  potassium  bichromate  and 
hydrochloric  acid,  as  well  as  by  the  use  of  a  galvanic  battery. 

To  Cut  Out  Iron  Plates  with  the  Assistance  of  Sulphuric  Acid. — 
A  mixture  of  1  part  by  weight  of  sulphuric  acid  and  6  of  water 
dissolves  steel  and  iron.  Now,  by  coating  an  iron  or  steel  plate 
with  a  thin  layer  of  wax,  drawing  any  design  desired  in  the  wax 
and  placing  the  plate  in  the  above-mentioned  fluid  for  several 
hours,  the  portions  constituting  the  design  will  drop  out.  Letters, 
names  and  ornaments  upon  sword  blades,  etc.,  are  etched  in  this 
manner. 

To  Make  a  Hole  in  Hard  Steel. — Prepare  a  mixture  of  sulphate 
of  copper,  1  oz.  ;  alum,  oz.  ;  powdered  common  salt,  half  a 
teaspoonful  ;  vinegar,  1  gill ;  and  nitric  acid,  20  drops.  This  will 
make  the  hole,  or,  if  washed  off  quickly,  will  give  a  beautiful 
frosted  appearance  to  the  metal. 

To  Detach  Gold  from  Gilt  Metallic  Articles. — Apply  to  the 


500 


THE  METAL  WORKER’S  HANDY-BOOK. 


articles  a  concentrated  solution  of  sal-ammonic  in  vinegar  and 
heat  to  a  dark-red  heat ;  then  throw  them  into  cold,  very  dilute 
sulphuric  acid,  whereby  the  gold  becomes  detached  in  thin  scales. 
The  latter  are  fused  with  saltpetre  and  borax,  whereby  the  gold  is 
obtained  in  a  coherent  form. 

To  Give  Metals — Lead,  Tin,  Zinc,  etc. — the  Capacity  of  Firmly 
Adhering  to  Other  Metals,  and  to  Amalgamate  with  them. — For 
this  purpose  sal-ammoniac,  phosphorus  and  borax  are  added  to  the 
metals  when  in  a  melted  state.  To  prevent  as  much  as  possible 
the  oxidation  of  the  fused  metal  and  the  volatilization  of  the  above- 
mentioned  agents,  the  surface  is  covered  with  pulverized  wood  or 
animal  charcoal. 

To  Keep  Steel  from  Rusting. — Brush  the  steel  with  a  solution 
of  paraffine  in  benzine.  This  is  transparent,  and  does  not  disfigure 
the  work  as  does  tallow  or  white-lead. 

To  Prevent  Metals  from  Rusting. — The  following  is  said  to  be 
a  good  application  to  prevent  the  rusting  of  metals:  Melt  i  oz. 
of  resin  in  a  gill  of  linseed  oil,  and  while  hot  mix  with  it  2  quarts 
of  kerosene  oil.  This  can  be  kept  ready  to  apply  at  any  time  with 
a  brush  or  rag  to  any  tools  or  implements  required  to  lay  by  for  a 
time,  preventing  any  rust,  and  saving  much  vexation  when  the  tool 
is  to  be  used  again. 

To  Prevent  Rusting  In  of  Screws. — In  machines  exposed  to  heat 
or  moist  air  the  screws  soon  rust  in,  even  with  the  use  of  oil,  which 
later  on  renders  it  difficult  to  take  the  machines  apart.  By  dipping 
the  screws  before  use  in  a  thin  paste  of  graphite  and  oil,  they  can 
be  readily  taken  out  even  after  years. 

To  Loosen  Rusted  Screws. — One  of  the  simplest  and  readiest 
ways  of  loosening  a  rusted  screw  is  to  apply  heat  to  the  head  of 
the  screw.  A  small  bar  or  rod  of  iron,  flat  at  the  end,  if  reddened 
in  the  fire  and  applied  for  2  or  3  minutes  to  the  head  of  the  rusty 
screw  will,  as  soon  as  it  heats  the  screw,  render  its  withdrawal  as 
easy  by  the  screw-driver  as  if  the  screw  had  been  only  recently 
inserted. 

To  Prepare  Good  Crucibles. — Excellent  and  refractory  crucibles 
and  retorts  can  be  prepared  from  a  mixture  of  2  parts  of  pipe-clay 


MISCELLANEOUS. 


501 


and  i  of  quartz  sand  ;  the  latter  must,  however,  be  of  sufficient 
fineness  to  pass  through  the  eye  of  a  large  needle.  Crucibles  pre¬ 
pared  according  to  this  direction  withstand  the  strongest  fire  of  a 
wind-furnace. 

To  Purify  Gold  in  the  Dry  Way  {by  CementatioTi),  According  to 
Philipp.— -Make  an  intimate  mixture  of  brick-dust,  3  parts;  sea 
salt,  1  ;  alum,  1;  and  green  vitriol,  1,  the  salts  being  thoroughly 
dried  before  being  mixed  with  the  brick-dust.  The  mixture  is  then 
formed  with  a  little  wine  vinegar  to  a  paste,  in  the  midst  of  which 
the  gold  to  be  purified  is  placed ;  if  the  gold  is  in  several  pieces, 
the  latter  are  distributed  throughout  the  mass.  Gold  of  from  8  to 
12  carats  is  best  adapted  for  this  mode  of  dry  parting.  Finer  gold 
must  first  be  alloyed  with  copper  until  it  shows  the  above-mentioned 
carat.  With  gold  alloys  of  less  than  8  carats,  the  particles  of  gold 
are  difficult  to  separate  from  the  cement  after  cementation.  Cemen¬ 
tation  is  effected  in  a  crucible  at  a  moderate  red  heat.  After 
cooling  the  porous,  chemically  pure  gold  is  freed  from  the  cement 
by  means  of  boiling  water  and  finally  melted  with  borax  to  a  dense 
mass. 

To  Repair  Cracked  Church  Bells. — The  process  of  repairing  a 
cracked  church  bell  so  that  its  tone  will  be  completely  restored 
consists  in  placing  a  furnace  in  the  interior  of  the  bell  so  as  to  heat 
and  fuse  the  edges  of  the  crack,  and  pouring  new  bell-metal  in 
the  crack.  To  prevent  the  escape  of  liquid  metal  the  wall  of  the 
bell  must  be  provided  with  suitable  contrivances. 

To  Restore  Burnt  Cast-steel. — For  this  purpose  a  powder  is  used 
which  consists  of  saltpetre,  8  parts  ;  colophony,  4 ;  and  dragon’s 
blood,  r.  Heat  the  article  to  a  dark-red  heat  and  dust  it  with  the 
above-mentioned  finely  pulverized  mixture.  When  the  powder  is 
absorbed  the  article  is  thoroughly  worked  upon  the  anvil.  A 
brown,  uniform  mixture  obtained  by  fusing  together  colophony,  3 
parts,  and  boiled  linseed  oil,  2,  is  also  highly  recommended  for  the 
purpose.  By  dipping  the  red-hot  burnt  steel  into  this  mass,  and 
repeating  the  operation  it  is  completely  restored.  According  to 
another  method  the  burnt  steel  is  heated  to  a  red  heat  and  dusted 
with  a  mixture  of  8  parts  of  red  chromate  of  potassium,  4  of  salt- 


302 


TITE  METAL  WORKER’S  IIANDY-BOOK. 


petre,  x/2  each  of  aloes  and  gum  arabic,  and  %  of  resin.  Then 
heat  the  article  several  times  and  cool  it.  If  the  article  is  to  be 
especially  hard  take  8  parts  of  saltpetre  and  3  of  resin. 

To  Restore  Burnt  Steel  Tools. — Melt  together  1  lb.  of  tallow  and 
4  ozs.  of  black  pitch,  and  then  add,  with  constant  stirring,  13  ozs. 
of  sal-ammoniac,  4  ozs.  of  yellow  prussiate  of  potash,  12  drachms 
of  soap  and  a  handful  of  common  salt.  The  red-hot  articles  are 
plunged  into  the  mass,  allowed  to  cool  therein,  and  then  again 
hardened  in  the  usual  manner.  For  large  tools  the  heating  and 
plunging  into  the  mass  must  be  repeated.  Another  mixture  which 
may  be  recommended  for  the  purpose  consists  of  resin,  10  parts ; 
fish  oil,  5  ;  tallow,  2  ;  assafoetida, 

To  Sharpen  Files. — Dull  files  may  be  sharpened  without  recut¬ 
ting  by  treating  them  with  acid  or  with  the  sand  blast. 

In  treating  files  with  acid  they  are  first  freed  from  adhering 
grease  by  scratch-brushing  with  the  use  of  potash  or  soda  lye. 
They  are  then  brought  into  an  oblong  box  of  a  material  not 
attacked  by  acids,  a  few  thin  glass  rods  or  varnished  sticks  of  wood 
being  first  placed  upon  the  bottom.  The  files  being  laid  alongside 
each  other,  sufficient  cold  water  to  cover  them  is  poured  into  the 
box,  the  eighth  part  of  concentrated  nitric  acid  is  then  added,  and 
after  mixing  water  and  acid  by  moving  the  box,  the  whole  is 
allowed  to  stand  quietly  for  25  minutes.  The  files  are  then  taken 
from  the  bath,  thoroughly  scratch-brushed  with  the  use  of  water 
and  replaced  in  the  box  for  25  minutes,  the  bath  having  previously 
been  strengthened  by  an  additional  eighth  part  of  nitric  acid. 
During  this  operation  care  must  be  had  to  several  times  turn  the 
files  and  to  see  that  they  are  entirely  covered  with  the  fluid.  The 
files  are  then  again  taken  from  the  bath,  thoroughly  cleansed  with 
a  scratch-brush  and  replaced  in  the  bath,  to  which  previously  the 
sixteenth  part  of  concentrated  sulphuric  acid  has  been  added. 
The  bath  now  becomes  heated,  and  red-brown  vapors  of  hyponi- 
tric  acid  escape.  Care  must  be  had  to  keep  the  box  in  a  rocking 
motion  so  that  the  acids  act  as  uniformly  as  possible.  After  5 
minutes  the  files  are  again  taken  out,  cleansed,  and  then  replaced 
for  5  minutes  more  in  the  same  bath,  previously  strengthened  by 


MISCELLANEOUS. 


503 


the  addition  of  one-sixteenth  part  more  of  concentrated  sulphuric 
acid ;  care  must  be  had  to  constantly  keep  the  bath  in  an  un- 
dulatory  motion.  The  operation  is  now  finished,  the  files  being 
finally  scratched-brushed,  and,  for  the  removal  of  every  trace  of 
acid,  placed  in  a  vessel  with  water  compounded  with  a  few  hand¬ 
fuls  of  caustic  lime,  which  gives  them  a  good  color.  They  are  then 
rinsed  in  clean  water,  dried  over  a  spirit-flame  and  rubbed  with  a 
little  oil. 

The  treatment  with  acid  may  also  be  effected  by  means  of  a 
galvanic  battery,  the  bath,  which  is  composed  of  water,  ioo  parts; 
nitric  acid,  80 ;  and  sulphuric,  40,  being  connected  with  the  positive 
pole.  The  negative  pole  is  formed  of  a  copper  spiral  passing 
around  the  files  without  touching  them,  and  with  the  end  pointing 
towards  the  surface  of  the  fluid.  By  using  a  galvanic  battery  of 
12  Bunsen  elements  10  minutes  suffice  for  the  treatment. 

The  Process  of  Sharpening  Files  with  the  Sand  Blast  consists  in 
forcing  with  great  rapidity  a  jet  of  fine  sand  against  the  file  to  be 
sharpened  by  means  of  a  jet  of  steam.  The  file  is  presented  to 
the  jet  of  sand  at  an  angle  of  from  40°  to  50°,  and  so  moved  that 
the  jet  of  sand  gradually  strikes  the  entire  surface.  The  sand 
used  for  the  purpose  must  be  very  fine  and  sharp,  and  prepared  by 
washing  and  elutriating.  It  is  used  in  the  shape  of  a  fine  mud 
kept  in  a  suitable  holder. 

Regarding  newly  cut  and  hardened  files  the  following  process 
may  be  mentioned,  whereby  the  breaking  out  of  the  teeth  is  as. 
much  as  possible  prevented :  Fill  an  iron  boiler  30  to  40  inches 
long,  6  to  8  inches  wide  and  of  a  corresponding  depth  with  well 
water.  Heat  the  contents  of  the  boiler  to  boiling  over  a  large 
wood-fire  which,  however,  should  strike  only  the  bottom  of  the 
boiler.  Now  add  to  the  water  8  ozs.  of  white  soap,  previously  dis¬ 
solved  in  warm  water,  and  4  ozs.  of  potash.  Then  pour  in  colza 
oil  until  the  entire  surface  of  the  contents  of  the  boiler  is  covered. 
The  hardened  and  cleansed  files,  secured  to  suitable  double  iron 
wires,  are  then  immersed  in  the  boiling  fluid  for  2  or  3  minutes,  when 
they  are  taken  out  and  laid  upon  a  table  or  a  board.  By  the  heat 
communicated  to  the  files  the  water  soon  evaporates,  whilst  the  oil 


504 


TIIE  METAL  WORKER'S  nANDY-BOOK. 


in  a  short  time  penetrates  through  the  cuts.  By  this  means  the 
teeth  become  more  elastic  and  do  not  break  so  readily. 

To  Sharpen  Tools. — Instead  of  oil,  which  thickens  and  smears 
the  stone,  a  mixture  of  glycerin  is  recommended.  The  propor¬ 
tions  of  the  composition  vary  according  to  the  class  of  tools  to  be 
sharpened.  One  with  a  relatively  large  surface  is  best  sharpened 
with  a  clear  fluid,  3  parts  of  glycerin  being  mixed  with  1  of 
spirits.  A  graver  having  a  small  cutting  surface  only  requires  a 
small  pressure  on  the  stone,  and  in  such  cases  the  glycerin  should 
be  mixed  with  only  2  or  3  drops  of  spirits. 

New  Method  of  Securing  Flues.- — It  is  the  usual  method  in  order 
to  secure  a  flue  in  a  boiler  to  expand  the  end  of  the  flue  into  a 
flange,  through  which  rivets  are  passed  to  secure  it  to  the  plate  of 
the  boiler.  It  is  obvious,  however,  that  in  thus  forming  a  flange 
on  the  end  of  the  flue  the  metal  will  be  reduced  in  thickness,,  and 
this  flanging  can  be  practically  done  only  for  purposes  where  a 
small  or  narrow  flange  will  suffice.  It  is,  however,  desirable  in 
many  cases  where  flues  or  tubes  or  pipes  are  used,  to  employ  forms 
thereof  having  flanges  much  wider  in  lateral  extent  than  would  be 
possible  to  forge  or  expand  from  the  body  of  the  tube  without 
reducing  the  stock  to  such  an  extent  that  the  flange  would  not 
have  the  requisite  strength  compared  with  the  body  of  the  tube. 
Thus  with  boiler  or  furnace  pipes  it  is  desirable  to  form  integral 
with  the  body  of  the  flue  the  bead  or  plate  that  is  to  form  a  part  of 
it  or  is  to  connect  it  with  the  fire  chamber  or  boiler  shell.  In  an 
invention  recently  patented,  the  plate  forming  the  head  is  formed 
with  a  circular  flange,  which  is  welded  to  the  flue  with  which  it 
forms  an  integral  part.  In  carrying  out  this  method  the  central 
portion  of  the  head-plate  is  first  cut  out  so  as  to  form  an  opening 
somewhat  smaller  than  the  flue.  The  edge  of  the  opening  is  thus 
bent  up  by  passing  a  forging  at  right  angles  to  the  body  of  the 
plate.  If  necessary,  two  flanged  openings  can  be  formed  in  the 
plate.  The  head  thus  prepared  is  then  welded  to  the  flue.  It  is 
claimed  that  the  flanged  or  headed  flue  thus  produced  is  a  much 
stronger  structure  than  the  flue  heretofore  produced,  and  has  the 
same  lateral  extent  of  flange  or  head,  and  it  obviates  all  the  objec- 


MISCELLANEOUS. 


505 


tions  incident  to  structures  of  similar  shape,  but  having  their  parts 
riveted  together. 

Solidification  of  Powdered  Metals. — According  to  W.  Spring,  the 
degree  of  pressure  required  to  unite  the  powders  of  the  respective 
metals  to  a  solid  mass  is  as  follows : 


Lead,  unites 

at  a  pressure  of  13 

Tin,  “ 

“  “  “  19 

Zinc,  “ 

“  “  “  38 

Antimony,  “ 

«  •<  « 

Aluminium,  “ 

“  “  “  38 

Bismuth,  “ 

“  «  “  38 

Copper,  “ 

“  “  “  33 

is  to  the  square  inch. 


Lead  becomes  liquid  with  a  pressure  of  33  tons  to  the  square 
inch,  and  tin  with  one  of  47  tons. 

Combustibility  of  Iron. — Combustibility  is  not  generally  con¬ 
sidered  one  of  the  properties  of  iron,  yet  that  metal  will,  under 
proper  conditions,  burn  readily.  The  late  Prof.  Magnus,  of  Berlin, 
Germany,  devised  the  following  method  of  showing  the  combusti¬ 
bility  of  iron  :  A  mass  of  iron  filings  is  approached  by  a  magnet 
of  considerable  power,  and  a  quantity  thereof  is  permitted  to  adhere 
to  it.  This  loose,  spongy  tuft  of  iron  powder  contains  a  large 
quantity  of  air  imprisoned  between  the  particles,  and  is,  therefore, 
and  because  of  its  extremely  comminuted  condition,  well  adapted 
to  manifest  its  combustibility.  The  flame  of  an  ordinary  spirit- 
lamp  or  Bunsen  burner  readily  sets  fire  to  the  finely  divided  iron, 
which  continues  to  burn  brilliantly  and  freely.  By  waving  the 
magnet  to  and  fro  the  showers  of  sparks  sent  off  produce  a  striking 
and  brilliant  effect. 

The  assertion  that  iron  is  more  combustible  than  gunpowder  has 
its  origin  in  the  following  experiment,  which  is  also  a  very  striking 
one  :  A  little  alcohol  is  poured  into  a  saucer  and  ignited.  A  mix¬ 
ture  of  gunpowder  and  iron  filings  is  allowed  to  fall  in  small 
quantities  at  a  time  into  the  flame  of  the  burning  alcohol,  when  it 
will  be  observed  that  the  iron  will  take  fire  in  its  passage  through 
the  flame,  while  the  gunpowder  will  fall  through  it  and  collect 


506 


TTTE  METAL  WORKER’S  II ANDY-BOOK. 


beneath  the  liquid  alcohol  unconsumed.  This,  however,  is  a 
scientific  trick,  and  the  experiment  hardly  justifies  the  sweeping 
assertion  that  iron  is  more  combustible  than  gunpowder.  The 
ignition  of  the  iron  under  the  foregoing  circumstances  is  due  to  the 
fact  that  the  metal  particles,  being  admirable  conductors  of  heat, 
are  able  to  absorb  sufficient  heat  during  their  passage  through  the 
flame — brief  as  it  is — and  they  are  consequently  raised  to  the 
ignition  point.  The  particles  of  the  gunpowder,  however,  are 
very  poor  conductors  of  heat,  comparatively  speaking,  and  during 
the  exceedingly  brief  time  consumed  in  their  passage  through  the 
flame  they  do  not  become  heated  appreciably,  or  certainly  not  to 
their  point  of  ignition.  Under  ordinary  circumstances,  gunpowder 
is  vastly  more  inflammable  than  iron. 

Another  method  of  exhibiting  the  combustibility  of  iron,  which 
would  appear  to  justify  the  assertion  that  it  is  really  more  combus¬ 
tible  than  gunpowder,  is  as  follows  :  Place  in  a  refractory  tube  of 
Bohemian  glass  a  quantity  of  dry,  freshly  precipitated  hydrated 
ferric  oxide.  Heat  this  oxide  to  bright  redness  and  pass  a  current 
of  hydrogen  through  the  tube.  The  hydrogen  will  deprive  the 
oxide  of  its  oxygen  and  reduce  the  mass  to  the  metallic  state.  If, 
when  the  reduction  appears  to  be  finished,  the  tube  is  removed 
from  the  flame  and  its  contents  permitted  to  fall  out  into  the  air,  it 
will  take  fire  spontaneously  and  burn  to  oxide  again.  This  experi¬ 
ment  indicates  that  pure  iron  in  a  state  of  the  extremest  subdivision 
is  one  of  the  most  combustible  substances  known,  more  so  even 
than  gunpowder  and  other  explosive  substances,  which  require  the 
application  of  considerable  heat  or  of  a  spark  to  ignite  them. 

Colors  Expressing  High  Temperatures. 


Faint  red . 

Orange .  ....... 

Dull  red . 

Bright  orange . 

Brilliant  red . 

. H70 

White  heat . 

Cherry  red . 

....  1650 

Bright  white  heat  .... 

. 2550 

Bright  cherry  red . 

MISCELLANEOUS. 


507 


Rails  anil  Fastenings  per  Mile  of  Railroad. 

RAILS  PER  MILE. 


Weight 

Gross  Tons 

per  yd. 

per  mile. 

65-lb . 

60  “ . 

.  94-3° 

56  “ . 

50  “ . 

.  78-57 

45  “ . 

.  7o.7i 

40  “ . . 

. 62.86 

35  “ . 

.  55-oo 

30  “ . 

.  47-14 

Weight  Gross  Tons 

per  yd.  per  mile. 

25-lb .  39.29 

20  “ .  31.43 

18  “ .  28.27 

16  “ .  25.14 

14  “ .  22.00 

12  “ .  18.85 

10  “ .  15.71 

8  “ .  12.59 


FASTENINGS  PER  MILE. 


Length  of  Rail. 


30  feet . 
28  “  . 
26  “  . 
24  “  . 
22  “  . 
21  “  . 
20  “  . 
18  “  . 


No.  of 
Joints. 

No. 

Splices 

No. 

Bolts. 

352 

704 

1,408 

377 

754 

1,508 

406 

812 

1,624 

440 

880 

1,760 

480 

960 

1,920 

503 

1,006 

2,012 

528 

1,056 

2,1 12 

587 

i,i74 

2,348 

No. 


11,264 
IL3I4 
n,372 
11,440 
11,520 
1 1,568 
11,616 
11,740 


INDEX 


Acetate  of  copper,  48,  49. 

of  lead,  42,  49. 

Acetic  acid,  60. 

Acid,  acetic,  60. 

arsenious,  51,  52. 

boracic,  60. 

boric,  60. 

chromic,  60. 

hydrochloric,  58,  59. 

hydrochloric,  use  of  as  a  flux,  418. 

hydrocyanic,  61. 

nitric,  57,  58. 

nitro-muriatic,  59,  60. 

oxalic,  61. 

phosphoric,  use  of  as  a  flux,  418. 
-proof  bronze,  116. 

-proof  cement,  234. 
prussic,  61. 
sulphuric,  56,  57. 

sulphuric,  to  cut  out  iron  plates 
with  the  assistance  of,  499. 
tartaric,  60. 

to  sharpen  files  with,  502,  503. 
Acids,  56-61. 

alkalies,  etc.,  coating  for  bars  of 
spring  steel  not  acted  upon  by, 
406. 

cleansing  metals  by  means  of,  with 
the  use  of  a  galvanic  current, 
242,  243. 
definition  of,  42. 
dipping  with,  319. 
testing  of,  74. 

Adams’  nickel-plating  salt,  486. 

Aich  or  sterro-metal,  99. 

Albata  metal,  114. 

Alder,  specific  gravity  of,  227. 

Alfenide,  argiroide  and  allied  alloys, 
113,  114. 

Alkalies,  acids,  etc.,  coating  for  bars  of 
spring  steel  not  acted  upon  by, 
406. 

Alloy,  Bourbonne’s  aluminium,  108. 
Delalot’s,  102. 
for  antifriction  brasses,  91. 
for  casting  small  articles,  1 16. 
for  cold  soldering,  4.7,  428. 


Alloy  for  dental  plates,  107,  108. 

for  moulds  for  pressed  glass,  116. 
for  silvering,  379,  380. 
for  spoons,  102. 

Gedge’s,  for  ship  sheathing,  100. 
Hoyle’s,  for  pivot  bearings,  91. 
Lemarquand’s  non-oxidizable,  119. 
Lipowitz’s,  83. 

Marley’s  non-oxidizable,  119. 
non-oxidizable,  122. 
of  copper  and  antimony,  116,  117. 
readily  fusible,  83. 
resembling  German  silver,  108. 
resembling  silver,  102,  108. 
soft,  for  coating  metals,  etc.,  122, 
123. 

tenacity  of  an,  80,  81. 
variation  in  color  of,  79. 
white,  closely  resembling  silver, 
103. 

white,  resisting  the  action  of  vege¬ 
table  acids,  114. 

Alloys,  79-123. 

and  amalgams,  79-126. 
and  metals,  resistance  of,  to  calcium 
hydrate,  77. 
definition  of,  79. 

exhibiting  greater  density  than 
their  constituents,  80. 
exhibiting  less  density  than  their 
constituents,  80. 

for  bronze  powders,  composition  of, 
160. 

for  calico-printing  rollers,  117. 
for  hot  leading,  354. 
for  small  patterns  in  foundries,  117. 
fusibility  of,  79. 

fusing  points  of  the  principal 
metals  and  other  elements  em¬ 
ployed  in,  82. 

in  gilding,  detection  of,  74,  75. 
manganese,  110-112. 
metallic,  directions  for  the  deter¬ 
mination  of  the  constituents  of, 
etc.,  66-78. 
new,  119,  120. 

new  method  of  preparing,  121. 

(509) 


510 


INDEX. 


Alloys,  non-magnetic,  for  watches,  121. 
of  antimony  and  lead,  polishing  of, 
209. 

of  bismuth  and  cadmium,  82,  83. 
of  copper  and  tin,  83-97. 
of  copper  and  zinc,  97-100. 
of  copper  with  silver  and  gold,  100- 
102. 

of  nickel,  112-115. 
of  nickel  and  steel,  114,  115. 
preparation  of,  81,  82. 
specific  gravity  of,  79,  80. 
table  of  colors  of,  for  statuary 
bronze,  93. 

used  by  the  metal-worker,  33. 
various,  116-123. 

Wood’s,  83. 

Alumina,  testing  for,  68. 

Aluminium  alloys,  103-109. 
alloys,  various,  107-109. 
bath,  325. 
brasses,  103,  104. 
bronze,  104-106. 
bronze,  casting  of,  209-213. 
bronze,  Hulot’s  solder  for,  424. 
bronze  jewelry,  solders  for,  424. 
bronze,  soft  solder  for,  424. 
bronze,  soldering  of,  423,  424. 
bronzes,  directions  for  preparing, 
105,  106. 

fusing  point  of,  82. 
powdered,  solidification  of,  505. 
solders  for,  423. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
-  323. 

symbol  and  atomic  weight  of,  40. 
to  engrave,  310. 

Amalgam,  definition  of,  79. 

Amalgams,  123-126. 
and  alloys,  79-126. 

American  welding  compound  for  steel, 
433. 

Ammonia,  61. 

hydrosulphate  of,  62. 
sulphydrate  of,  62. 

Ammoniacal  liquor,  61. 
Ammouio-chloride  of  platinum,  55. 

-ferrous  sulphate,  45. 

Ammonium,  61. 

phosphate,  61,  62. 
sulphide,  62. 

Ampgres,  definition  of,  323. 

Amtmann,  enamel  for  cast-iron  pipes, 
according  to,  302. 

Annealing,  hardening  and  tempering, 
126-147. 

of  wire,  451,  452. 


Anode,  definition  of,  323. 

Anti-friction  brasses,  alloy  for,  91. 
Antimony  and  lead  alloys,  polishing 
of,  269. 

arsenic  and  zinc,  preparations  of, 
51,  52. 
baths,  325. 
butter  of,  51. 
colors  on  brass,  177. 
determination  of,  69. 
fusing  point  of,  82. 
powdered,  solidification  of,  505. 
regulus,  resistance  of  to  calcium 
hydrate,  77. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

symbol  and  atomic  weight  of,  40. 
trichloride,  51. 

Apple-tree  wood,  specific  gravity  of, 

227. 

Aqua  fortis,  57,  58. 
regia,  59,  60. 
regia,  preparation  of,  39. 

Argent  fran§ais,  101,  102. 

-Ruolz,  101,  102. 

Argentan  solders,  424. 
white,  114. 

Argentic  chloride,  53. 
oxide,  53. 

Argentiferous  pastes  for  cold  silvering, 
composition  of,  372,  373. 
Argentum  musivum,  162. 

Argiroide,  alfenide  and  allied  alloys, 
113,  114. 

Armenian  or  jeweller’s  cement,  240,  241. 
Arsenic,  antimony  and  zinc,  prepara¬ 
tions  of,  51,  52. 
baths,  325,  326. 
determination  of,  69,  70. 
flux  for  reducing,  396. 
fusing  point  of,  82. 
specific  gravity,  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

symbol  and  atomic  weight  of,  40. 
white,  51,  52. 

Arsenical  compounds,  fluxes  for,  396. 
Arsenious  acid,  51,  52. 

Ashberrv  metal,  109,  110. 

Asphalt  lacquer  on  iron,  401. 

varnish,  bright,  for  sheet-metals, 
411. 

Atomic  weights  and  symbols  of  the 
most  important  elements,  40. 
weights,  definition  of,  41. 

Augsburg  brass  wire,  99. 
brouze,  93. 


INDEX. 


611 


Auric  chloride,  54. 

Aurous  chloride,  54. 

Aurum  muriaticuru  natronatum  crvs- 
tallisatum,  54,  65. 
musivum,  161,  162. 

Austrian  government  railroad,  white 
metal  bearings  used  by,  89. 

Axle-arms,  to  case-harden,  131. 
boxes,  Fenton’s  alloy  for,  91. 
journals,  Austrian,  98. 

Axles  and  tires,  electric  welding  of, 
439. 

heavy,  white  metal  bearings  for,  89. 
railroad,  bearings  for,  88. 
rapidly  revolving,  white  metal 
bearings  for,  89. 
various,  bearings  for,  88. 

Babbitt’s  anti-attrition  metal,  90,  91. 

Bacchus,  statue  of,  93. 

Barbed  wire,  manufacture  of,  illus¬ 
trated  and  described,  453-455. 

Barff  process  for  preserving  iron  and 
steel  from  rust,  297,  298. 

Barium,  symbol  and  atomic  weight  of, 
40. 

Barnard  damask,  illustrated,  281. 

Barrel  hoops,  electric  welding  of,  439. 

Bases,  definition  of,  42. 

Basic  open-hearth  steel,  manufacture 
of,  474,  475. 

Batteries,  management  of,  322,  323. 
preparation  of  zinc  for,  324,  325. 
storage,  constructed  by  M.  de 
Bernados,  illustrated  and  de¬ 
scribed,  441,  442. 

used  for  electro-deposition,  320-322. 

Beams,  contraction  of,  in  casting,  191. 

Bearing  metals  for  locomotives,  89. 

Bearings,  metals  for,  88,  89. 
of  great  hardness,  89. 
of  rapidly  running  machines,  ap¬ 
proved  compositions  for,  89. 
red  brass,  88. 
white  metal,  89. 

Beech,  specific  gravity  of,  227. 

Belgian  bearing  metal  for  locomotives, 
89. 

polishing  powder,  270. 

Belgium,  nickel  coins  of,  112. 

Beil  founding,  207-209. 

-metal,  85-87. 

-metal,  for  church  and  other  large 
bells,  86. 

-metal,  founder’s  standard,  86. 
-metal,  standard,  86. 

-metal,  very  deep  toned  and 
sonorous,  86. 


Bell-metals,  table  of  composition  of, 

86. 

Bells,  metal  for,  90. 

moulding  of,  208,  209. 
peals  of,  207. 
small,  metal  for,  86. 
weights  of,  208. 

Benzine,  62. 

Benzole,  62. 

Berlin  blue,  46. 

German  silver,  112. 

Bernados’,  de,  and  Olszewsky’s  method 
of  electric  welding,  illustrated 
and  described,  440-444. 

M.  de,  storage  batteries,  constructed 
by,  illustrated  and  described, 
441,  442. 

Bertrand,  mechanical  silvering  accord¬ 
ing  to,  378. 

Biddery  metal,  109,  110. 

Birmingham  Britannia  metal,  109. 
or  Stubs  wire  gauge,  460. 
platinum,  117. 
silvering,  377,  378. 

Bismuth  alloys,  83. 

and  cadmium,  alloys  of,  82,  83. 
cement  for  cementing  the  glass 
parts  on  petroleum  lamps,  240. 
contraction  of,  in  casting,  192. 
determination  of,  69. 
fusing  point  of,  82. 
lead  and  tin,  preparations  of,  49, 
50. 

nitrate,  50. 

powdered,  solidification  of,  505. 
solder,  421. 

symbol  and  atomic  weight  of,  40. 
Black  flux,  394,  395. 
lead,  63. 

Blacksmiths,  locksmiths  and  founders, 
iron  lacquer  for,  403. 

Blanching,  371,  372. 

Blast  pipes,  hot  blast  stoves,  blowing 
engines,  etc.,  cement  for,  229. 
Blocks,  445. 

Blowing  engines,  blast  pipes,  hot  blast- 
stoves,  etc.,  cement  for,  229. 
Blow-pipe,  use  and  description  of,  417. 
Blue  bronze,  150,  151. 
vitriol,  42,  47,  48. 

Bolts,  number  of,  per  mile  of  railroad, 
507. 

Boracic  acid,  60. 

Borax,  62. 

use  of,  as  a  flux,  418. 

Bores  of  musket-barrels,  to  harden, 
141. 

Boric  acid,  60. 


512 


INDEX. 


Boron,  symbol  and  atomic  weight  of, 
40. 

Bourbonne’s  aluminium  alloy,  108. 

Boxes  for  wagon-wheels,  metal  for,  88. 

Boxwood,  specific  gravity  of,  227. 

Brass  and  bronzes,  coloring  of,  173. 
and  copper,  brown  fire-proof  bronze 
upon,  153. 

and  copper,  new  bronze  color  upon, 
179. 

and  copper  parts,  cement  for,  238. 
and  copper,  to  bronze  articles  of, 
153. 

and  copper,  to  color,  179,  180. 
and  copper,  to  whiten,  180. 
and  copper,  to  zinc  without  a 
battery,  387. 
and  glass,  to  unite,  234. 
and  similar  alloys,  97-100. 
and  similar  alloys,  table  of  compo¬ 
sition  of,  99,  100. 
antimony  colors  on,  177. 
articles,  small,  to  bronze,  151. 
articles,  to  cleanse,  272. 
bath  for  cast-iron,  wrought-iron 
and  steel,  327. 
bath  for  zinc,  326,  327. 
bath  from  cupric  sulphate  and 
zinc  sulphate,  326. 
baths,  326-328. 
beautiful  silver  color  on,  179. 
bronze,  Britannia  metal,  etc.,  prep¬ 
aration  of,  for  nickelling,  354, 
355. 

bronzing  liquids  for,  157,  158. 
brown  color  called  bronze  Barb6- 
dienue,  on,  174,  175. 
castings,  locomotive,  89,  90. 
cement  for  fastening,  to  glass,  236. 
color  resembling  gold  on,  174. 
contraction  of,  in  casting,  192. 
copper  and  tombac,  to  give  a  bril¬ 
liant  appearance  to,  254. 
copper,  iron,  nickel  bath  for,  358. 
copper  or  bronze,  to  coat  iron 
articles  with,  336,  337. 
copper,  silver,  etc.,  gilding  powder 
for,  348. 

deep  black-blue  stain  on,  178. 
deposits,  color  of,  327. 
dipping  of,  318. 

Ebermayer’s  method  of  coloring, 
175,  176. 

English  process  of  pickling,  252, 
253. 

etching  on,  311. 

etching  solution  for,  313,  314. 

for  sheet  and  wire,  97. 


Brass,  German  silver,  tombac  and 
copper,  polishing  of,  268. 
gold  and  orange  stains  for,  179. 
gray  color  with  a  bluish  tint  upon, 

174. 

green  bronze  for,  152,  153. 
instruments,  dead  black  on,  177, 

178. 

lacquers  for,  402. 

lustrous  black  on,  173. 

lustrous  gold  or  green  on,  178, 

179. 

malleable,  119. 

mixture  for  a  dull-grained  surface 
on,  319. 

moir6  on,  285,  286. 
nuts,  casting  screws  on,  203,  204. 
old,  to  cleanse,  272. 
or  bronze  wire,  phosphorized,  456. 
or  copper  objects,  to  tin,  382. 
parts,  method  for  cleaning,  in  the 
United  States,  253. 
pickle  for  a  dead  lustre  for,  319. 
pickling  of,  251,  252. 
polish  for  pressed  articles  of,  274. 
polishing  paste  for,  272. 
red,  87,  111. 

red,  aud  similar  alloys,  table  of 
composition  of,  98. 
resistance  of  to  calcium  hydrate, 
77. 

sheet,  to  cut  by  chemical  means, 
499. 

sheet,  to  roughen  for  painting,  499. 
steel-gray  on,  173. 
straw-color  to  brown  through 
golden  yellow  and  tombac  color 
on,  174. 

to  brighten  and  color,  176,  177. 
to  color,  violet  and  cornflower-blue, 

175. 

to  lacquer,  401,  402. 
to  temper,  147. 
to  test,  73,  74. 
various  colors  upon,  170. 
very  tenacious,  99. 
watch  cases,  gold-colored  lacquer 
for,  402. 
wire,  99. 

wire,  method  of  making,  464. 
yellow,  contraction  of,  in  casting, 
191. 

Brasses  for  driving  boxes,  90. 
for  side  rods,  89. 

Brassing,  coppering,  galvanizing,  gild¬ 
ing,  nickelling,  silvering,  'in¬ 
ning,  electro-plating,  etc.,  317- 

394. 


INDEX. 


513 


Brassing,  coppering,  electroplating, 
galvanizing,  manufacture,  etc., 
of  wire,  445-473. 

of  wire  in  the  galvanic  way,  463, 
404. 

Brazier’s  hearth,  416. 

Brazil,  nickel  coins  of,  112. 

Brazing,  definition  of,  414. 

Bright  Platinum  Plating  Co.,  of  Lon¬ 
don,  platinum  bath  patented  by 
the,  365. 

Brilliants,  Fahlun  or  tin,  118. 

Bristol  brass,  99. 

Britannia  metal  and  similar  alloys,  109, 

110. 

ware,  brass  and  bronze,  preparation 
of,  for  nickelling,  354,  355. 
wares,  polishing  agent  for,  270. 
British  plate  metal,  114. 

Brocade  bronze  power,  160,  161. 
Bromine,  symbol  and  atomic  weight  of, 
40. 

Bronze,  acid-proof,  116. 
aluminium,  104-106. 
aluminium,  casting  of,  209-213. 
annealing  of,  127,  128. 

Barbedienne  on  brass,  174,  175. 
best  for  statues,  94. 
blue,  150,  151. 
bluish-gray  for  copper,  152. 
brass  and  Britannia  ware,  prepara¬ 
tion  of,  for  nickelling,  354,  355. 
brass  or  copper,  to  coat  iron  arti¬ 
cles  with,  336,  337. 
brown,  151. 

brown  fire-proof,  upon  copper  and 
brass,  153. 
cheap,  151. 

copper,  upon  iron  and  zinc,  149. 

damasked,  283. 

definition  of,  83. 

dipping  of,  318. 

fixtures  to  cleanse,  245. 

for  electrotypes,  156. 

for  gilding,  94. 

for  small  castings,  94. 

French,  149,  150. 
genuine  gold,  161. 
gold,  95,  148. 
green,  for  brass,  152,  153. 
green,  on  tin,  zinc  and  lead,  149. 
Japanese,  95. 
liquid,  151. 
machine,  87-92. 
malleable,  95,  96. 
manganese,  sheet  from,  100. 
melted,  bronzing  by  dipping  in, 
151. 

33 


Bronze,  old  Peruvian,  96. 

or  brass  wire,  phosphorized,  456. 
ordnance,  composition  of,  of  various 
times  and  countries,  84. 
pickling  of,  251. 
platinum,  122. 
powder,  brocade,  160,  161 
powder,  genuine  silver,  162. 
powder,  imitation  silver,  162. 
powders,  159,  160. 
powders,  brownish  gold,  162. 
powders,  composition  of  alloys  for, 
160. 

powders,  English,  160. 
red,  149. 
silver,  148,  149. 

statuarv,  table  of  colors  of  alloys 
for,  93. 

steel  or  Uchatius,  85. 

Walker’s  chemical,  159. 
which  can  be  rolled,  94. 

Bronzes,  aluminium,  directions  for  pre¬ 
paring,  105,  106. 
and  brass,  coloring  of,  173,  174. 
Chinese,  94. 

incrustes  (incrustations),  277,  278. 
Bronzing  and  coloring,  148—189. 

by  dipping  in  melted  bronze,  151. 
cast-iron,  154. 
green,  153,  154. 
in  Paris  mint,  151,  152. 
liquids,  Graham’s,  157,  158. 
Rockline’s  method  of,  159. 

Brown  &  Sharpe’s  wire  gauge,  460. 
Brown  bronze,  151. 

Brownish  gold  bronze  powders,  162. 
Buff  wheels,  257. 

Bunsen’s  battery,  illustrated  and  de¬ 
scribed,  321,  322. 

Burnisher  or  burnishing  stone,  polish¬ 
ing  with  the,  259-262. 
Burnishing  cutlery,  262,  263. 
silver,  263. 

stone  or  burnisher,  polishing 
with  the,  259-262. 
tools,  illustrated  and  described, 
260,  261. 

Butter  of  antimony,  51. 

Buttons,  metal  for,  88. 
sheet  for,  98. 

Tournay’s  metal  for,  98. 

Cadmium  and  bismuth,  alloys  of,  82, 

83. 

determination  of,  69. 
fusing  point  of,  82. 

Calcium  hydrate,  resistance  of  metals 
and  alloys  to,  77. 


514 


INDEX. 


Calcium,  potassium  and  sodium  sul¬ 
phides,  62. 

symbol  and  atomic  weight  of,  40. 
Calico  printing  rollers,  alloys  for, 
117. 

Calin,  117. 

Callot’s  etching-ground,  311. 
Caoutchouc,  62,  63. 

Caput  luortuum,  256. 

Carbon,  amount  of,  permissible  in  steel 
for  wire,  446. 
bisulphide,  63. 

holder,  illustrated  and  described, 
442-444. 

symbol  and  atomic  weight  of,  40. 
Carbonate,  copper,  48. 
lead,  49. 
silver,  53. 

Carlsso n -Bessemer  process,  475,  476. 
Carriage  work,  electric  welding  of, 
439. 

Case-hardened  or  hard  steel  articles, 
tinning  of,  383,  384. 
Case-hardening  axle-arms,  131. 
compound,  new,  142. 
wrought-iron,  128-131. 

Cassius,  purple  of,  55. 

Cast-brass,  French,  100. 

Casting  aluminium  bronze,  209-213. 
and  founding,  189-228. 
brass-nuts  on  screws,  203,  204. 
Germau  silver  for,  113. 
improved  method  of  treating  steel 
for,  228. 

metals,  apparatus  for,  illustrated 
and  described,  224,  225. 
on  to  other  metals,  204,  205. 
shrinking  of  metals  in,  189-192. 
small  articles,  alloy  for,  116. 
Castings,  brass,  99. 

cement  for  repairing  defective 
places  in,  23.. 

copper,  dense  and  flexible,  214. 
core  for  difficult,  201,  202. 
easy  rule  to  find  weight  of,  192. 
heavy,  cores  in,  201. 
iron,  annealing  of,  126,  127. 
mitis,  214-217. 

of  ingot-iron,  moulding  sand  for, 
192. 

small,  bronze  for,  94. 
small,  metal  for,  88. 
subjected  to  steam  pressure,  metal 
for,  90. 

to  be  gilded,  metal  for,  88. 
to  fill  up  holes  in,  206,  207. 
to  repair,  by  burning  on,  206. 
tombac  for,  98. 


Castings,  weight  of,  192. 

without  core,  illustrated  and  de¬ 
scribed,  202,  203. 
wrought-iron,  214-217. 

Cast-iron  articles,  enamel  as  prepared 
in  England  for,  300. 
bronzing  of,  154. 
inoxidizing  process  for,  296,  297. 
malleable,  476-479. 
objects,  to  solder,  425. 
or  wrought-iron  articles,  pickle 
for,  250. 

pure,  resistance  of,  to  calcium 
hydrate,  77. 
soldering  of,  424,  425. 
steel  and  wrought-iron,  ready  dis¬ 
tinction  of,  75. 

tin  or  zinc,  to  coat  with  copper, 
337. 

tinned,  or  fonte  argentine,  to 
make,  386. 
to  bronze,  154. 
to  copper,  336. 
to  harden,  131,  132. 
to  mould  lace  in,  200,  201. 
uteusils,  to  enamel,  299-301. 
wrought-iron  and  steel,  brass 
bath  for,  327. 

Cast-steel,  burnt,  to  restore,  501,  502. 
to  weld,  432,  433. 

with  cast-steel,  to  unite  by  weld¬ 
ing,  434. 

with  iron,  to  unite  by  welding, 
434. 

Cathode,  definition  of,  323. 

Caustic  potash,  64. 
soda,  64. 

Cedar,  red  Honduras,  specific  gravity 
of,  227. 

Cement,  acid-proof,  234. 

fire-proof  and  water-proof,  233. 
for  uniting  iron  surfaces  and  filling 
in  joints,  229. 
glass,  83. 
metallic,  83. 

Cementation,  to  purify  gold  by,  501. 

Cements,  228-241. 

Chalk,  257. 

Chandeliers  and  gas-fixtures,  to  cleanse, 
246. 

Chemical  and  electro  chemical  equiva¬ 
lents,  table  of,  323. 
combinations,  expression  of,  41. 
or  electrical  apparatus,  cement  for, 
234. 

relations  of  metals,  33-45. 

Chemicals  and  substances  used  in  the 
metal  industry,  various,  61-66. 


INDEX. 


515 


Chemicals  and  the  most  important 
metallic  preparations  used  in  the 
metal  industry,  45-66. 

Chenot’s  iron  cement,  230. 

Cherry-tree  wood,  specific  gravity  of, 
227. 

Chilled-wheels,  manufacture  of,  219— 
223. 

Chills,  preparation  of,  for  casting 
metal,  225. 

China,  ordnance  bronze  of,  84. 

sheet-brass  from,  99. 

Chinese  bronzes,  94. 

German  silver,  113. 
speculum  metal,  97. 
tam-tams  or  gongs,  85,  86. 

Chisels,  bath  used  in  tempering  and 
heating,  144. 

Chloride,  argentic,  53. 
auric,  54. 
aurous,  54. 
cobaltous,  46,  47. 
cupric,  48. 
cuprous,  48. 
ferric,  45,  46. 
ferrous,  45. 
lead,  49,  50. 
mercuric,  52. 
nickel,  47. 

of  copper,  how  obtained,  38. 

of  gold,  39,  54. 

of  lead,  39. 

of  platinum,  39,  55. 

of  silver,  39,  53. 

of  zinc,  51. 

of  zinc,  formation  of,  38. 
of  zinc,  use  of,  as  a  flux,  418. 
platinic,  55. 
stannous,  50. 

Chlorides,  metallic,  definition  of,  37. 
metallic,  preparation  of,  illustrated 
and  described,  37,  38. 

Chlorine,  combinations  of  metals  with, 
36-39. 

combustion  of  Dutch  gold  in,  37. 
preparation  of,  36,  37. 
symbol  and  atomic  weight  of,  40. 
water,  solution  of  genuine  gold  in, 
37. 

Chromate,  lead,  43,  50. 

Chrome  yellow,  43,  50. 

Chromic  acid,  60. 

Chromium,  testing  for,  68. 
Chrysochalk,  98. 

Chrysorin,  99. 

Church-bells,  cracked,  to  repair,  501. 
Clay,  Stourbridge,  397. 
use  of,  as  a  flux,  418. 


Cleansing,  grinding,  pickling,  polish¬ 
ing,  241-277. 

Cliche  metal,  83. 

Clock  bells,  table  bells,  sleigh  bells, 
etc.,  86,  87. 
wheels,  99. 

Coal-tar,  light  oil  from,  62. 

Cobalt  and  nickel,  preparations  of,  46, 
47. 

baths,  328,  329. 
determination  of,  67,  68,  74. 
electroplating  with,  by  contact, 
329. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

symbol  and  atomic  weight  of,  40. 
Cobaltous  chloride,  46,  47. 
nitrate,  47. 
oxide,  47. 

Cochin-China,  ordnance  bronze  of,  84. 
Cocks,  metal  for,  88. 

Cog-wheels,  metal  for,  88. 

Coins  and  medals,  to  brown,  188,  189. 
medals  and  articles  of  silver,  cleans¬ 
ing  of,  245. 

medals,  etc.,  matrix  mass  for  the 
reproduction  of,  495. 
fineness  of,  100. 
nickel,  112. 

Colcothar,  46,  256. 

Colophony,  use  of,  as  a  soldering  agent, 
418. 

Color,  beautiful  silver,  on  brass,  179. 
brown,  on  copper,  168. 
red-brown,  on  copper,  168,  169. 
resembling  gold  on  brass,  174. 
Colored  enamels,  304. 

Coloring  and  bronzing,  148-189. 

Colors  expressing  high  temperatures, 
506. 

iridescent  upon  metals,  283. 
Column  of  July,  93. 

Vendome,  93. 

Combination  of  the  elements,  laws  of, 

40,  41. 

Combinations,  chemical,  expression  of, 

41. 

Connecting-rods,  contraction  of,  in  cast¬ 
ing,  191. 

Cooper’s  alloy  for  steel-pens,  117. 
Copper,  acetate  of,  48,  49. 

alloys  of,  with  silver  and  gold, 
100-102. 

alloys,  pickle  for  bright  lustre  for, 
319. 

alloys,  preliminary  pickle  for, 
319. 


I 


516 


INDEX. 


Copper  amalgam,  123,  124. 

amalgam,  to  cement  with,  237. 
and  antimony,  alloy  of,  116, 
117. 

and  brass,  brown  fire-proof  bronze 
upon,  153. 

and  brass,  new  bronze  color  upon, 
179. 

and  brass  parts,  cement  for,  238. 
and  brass,  to  bronze  articles  of, 
153. 

and  brass,  to  color,  179,  180. 
and  brass,  to  zinc  without  a  battery, 
387. 

and  brass,  to  whiten,  180. 
and  nickel  alloys,  112. 
and  tin,  alloys  of,  83-97. 
and  tin,  contraction  of,  in  casting, 
191. 

and  zinc,  alloys  of,  97-100. 
articles,  desilvering  of,  488. 
bath  without  potassium  cyanide, 
331. 

baths,  329-331. 
black  upon,  170. 

brass,  German  silver  and  tombac, 
polishing  of,  268. 
brass,  iron,  nickel  bath  for,  358. 
brass  or  bronze,  to  coat  iron  articles 
with,  336,  337. 
bronze,  149. 
bronze  powder,  161. 
bronzing  liquids  for,  158. 
brown  color  upon,  168. 
browning  liquid  for,  170. 
carbonate,  48. 

castings,  dense  and  flexible,  214. 
chloride  of,  how  obtained,  38. 
coloring  of,  168. 
contraction  of,  in  casting,  192. 
cooking  tensils,  enamel  for,  303. 
cyanide  of,  49. 
dead-black  on,  170. 
deposit  on  wax,  334. 
determination  of,  69. 
dipping  of,  318. 

Elmore  process  of  electro-deposit¬ 
ing,  for  tubes  and  wire  bars,  331- 
334. 

engravers,  wax  mass  for,  310. 
engraving  on,  307,  308. 
etching  on,  311. 
for  joining  iron  to  iron,  428. 
fusing  point  of,  82. 

German  silver  or  silver,  ungilding 
articles  of,  486. 

massive,  various  colors  upon,  169, 
170. 


Copper  nitrate,  48. 

or  brass  objects,  to  tin,  382. 
phosphide  of,  preparation  of,  91. 
pickling  of,  251. 
powder,  47. 

powdered,  solidification  of,  505. 
precipitates,  iridescent  on  iron,  164, 
165. 

preparations,  47-49. 
recovery  of,  483,  4S4. 
red-brown  color  on,  16S,  169. 
silver,  brass,  etc.,  gilding  powder 
for,  348. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

steel-gray  upon,  169. 
sulphate  of,  47,  48. 
sulphide  of,  48. 

symbol  and  atomic  weight  of, 
40. 

testing  of,  74. 
to  bronze,  152. 
to  bronze  bluish-gray,  152. 
to  brown,  170. 

to  coat  tin,  cast-iron  or  zinc  with, 

337. 

to  color  blue-black,  169. 
to  color  dark  steel-gray,  169. 
to  harden,  128,  141,  142. 
to  make  steel  soft,  so  it  can  be 
worked  like,  127. 
to  platinize,  366. 
to  polish  and  color,  276. 
tombac  and  brass,  to  give  a  brilliant 
appearance  to,  254. 
to  weld,  435. 
wire,  to  solder,  428. 
wire,  weight  per  mile  of,  463. 
wire,  weight  per  1000  feet  of,  462. 
zinc  and  nickel  alloys,  112-114. 

Copper-zinc  alloy  serving  as  anode,  solu¬ 
tion  for  transferring  any,  327. 
alloys,  table  of  color  of,  98. 
alloys,  table  of  composition  of, 
98-100. 

Copperas,  45. 

Coppering,  brassing,  electroplating, 
galvanizing,  manufacture,  etc., 
of  wire,  445-473. 

brassing,  galvanizing,  gilding, 
nickelling,  silvering,  tinning, 
electroplating,  etc.,  317-394. 
zinc  plates,  337,  338. 
cast-iron,  336. 
iron,  335,  336. 
iron  and  steel,  336. 
of  iron  wire,  464,  465. 


INDEX. 


517 


Core,  casting  without,  illustrated  and 
described,  202,  203. 
for  difficult  castings,  201,  202. 

Cores  in  heavy  castings,  201. 

Cork,  specific  gravity  of,  227. 

Cornish  reducing  flux,  396. 

Corrosive  sublimate,  52. 

Corvin’s  niello,  278,  279. 

Cowles  Bros.’  tests  of  aluminium  brass, 
103. 

Cowrie,  specific  gravity  of,  227. 

Cramps,  etc.,  cement  for  fastening, 
230. 

Cream  of  tartar,  65. 

Crocus,  256. 

Crucibles,  good,  to  prepare,  500, 
501. 

Crucible  lids,  cement  for  luting,  240. 
Crude  flux,  396. 

Cryolite,  use  of,  as  a  flux,  418. 

Cuivre  fume,  169. 

Cupric  and  cuprous  oxides,  49. 
chloride,  48. 
oxide,  formation  of,  35. 
sulphate,  42,  47,  48. 
sulphate  and  zinc  sulphate,  brass 
bath  from,  326. 

Cupro-diammonium  sulphate,  48. 
Cupro-manganese,  110. 

Cuprous  and  cupric  oxides,  49. 
chloride,  48. 
oxide,  formation  of,  35. 
sulphide,  formation  of,  39. 

Cutch,  494. 

Cutlers’  baths  used  in  tempering  and 
heating  steel  articles,  144. 
Cutlery,  burnishing  of,  262,  263. 

fluid  for  hardening,  134,  135. 
Cyanide  of  copper,  49. 
of  gold,  54. 
of  silver,  53. 

Cylinders,  contraction  of,  in  casting, 
191. 

Daniell’s  battery,  322. 

Darby’s,  J.  H.,  experiments  in  the 
manufacture  of  basic  open-hearth 
steel,  474,  475. 

Darmstadt,  alarm-bell  at,  86. 

Damascus  gun-barrels,  illustrated  and 
described,  280,  281. 
steel,  imitation  of,  279,  280. 
Damask,  Barnard,  illustrated,  281. 
imitation  of,  282. 

production  of,  in  relief  upon  gun- 
barrels,  282. 

Turkish,  illustrated,  280. 
Damasked  bronze,  283. 


Damaskeened  surface  upon  steel-guns, 
282,  283. 

Damaskeening,  279. 

iron  and  steel  with  platinum, 
281. 

with  gold  or  silver,  281,  282. 

Dead-head  or  sullage  piece,  84. 

Decorating,  enamelling,  engraving, 
etching,  277-316. 

Delalot’s  alloy,  102. 

Delta-metal,  94,  95. 

Dental  plates,  alloy  for,  107,  108. 

Desilvering,  488. 

Dewrance’s  patent  bearing  for  loco¬ 
motives,  91, 

Dial-plates,  silvered,  to  cleanse,  245, 
246. 

Diamond  cement,  233. 

Dies  and  taps,  to  temper,  145,  146. 

Dipping  of  metals,  318-320. 

or  pickling  of  metallic  objects, 
250-254. 

Directions  for  the  determination  of  the 
constituents  of  metallic  alloys, 
impurities  of  the  technically 
most  important  metals,  etc.,  66- 
78. 

Drills,  small,  to  harden,  134. 

Driving-boxes,  brasses  for,  90. 

Drum,  tumbling,  illustrated  and  de¬ 
scribed,  258,  259. 

Drums  for  wire  drawing,  sizes  of,  452. 

Duncombe,  Nellie  C.,  invention  of 
decorating  metals  by,  287,  288. 

Dutch  bearing-metal  for  locomotives, 
89. 

gold,  combustion  of,  in  chlorine, 
37. 

Dysiot,  117,  118. 

Ebeling,  Bernhard,  of  Bremen,  barbed 
wire  manufactured  by,  454. 

Ebermayer’s  method  of  coloring  brass, 
175,  176. 

Eccentric  straps,  metal  for,  88. 

Ehrhardt’s  type  metal,  116, 

Electric  welding,  436-444. 

welding,  apparatus  used  in,  436- 
438. 

welding,  applications  of,  439. 
welding,  process  of,  438,  439. 
welding  under  water,  441. 
welds,  strength  of,  439,  440. 

Electrical  conduits,  flexible  insulating 
mass  for,  493. 

conduits,  insulating  material  for, 
493. 

horse  power,  definition  of,  323. 


518 


INDEX. 


Electrical,  or  chemical  apparatus, 
cement  for,  1434. 

Electricity,  direct  system  of  generating, 

437. 

indirect  system  of  generating,  437, 

438. 

for  welding,  generation  of,  436, 
437. 

to  temper  steel  by,  145. 

Electro-brassing  of  wire,  464. 

-chemical  and  chemical  equiva¬ 
lents,  table  of,  323. 

-deposition,  batteries  used  for,  320- 
322. 

-deposition  of  metals,  preliminary 
conditions  necessary  for  the,  317, 
318. 

Electrohephestos,  a  new  method  of 
electric  welding,  illustrated  and 
described,  440-444. 

Electrolytic  deposition  of  metals,  terms 
used  in,  323. 

Electro-plating  baths,  aluminium,  325. 
antimony,  325. 
arsenic,  325,  326. 
brass,  326-328. 
cobalt,  328,  329. 
copper,  329-331. 
gold,  238-342. 
iron,  349-351. 
lead,  351. 
nickel,  354-360. 
platinum,  365,  366. 
silver.  368-370. 
steel,  349-351. 
tin,  380,  381. 
zinc,  386,  387. 

Electro-plating,  brassing,  coppering, 
galvanizing,  gilding,  nickelling, 
silvering,  finning,  etc.,  317-394. 

galvanizing,  coppering,  brassing, 
manufacture,  etc.,  of  wire,  445- 
473. 

with  cobalt  by  contact,  329. 

Electrotypes,  to  bronze,  156. 

Electrtim,  113. 

Elements,  definition  of,  40. 

fusing  point  of  principal,  employed 
in  alloys,  82. 

laws  of  combination  of  the,  40,  41. 

table  of  the  most  important  with 
their  symbols  and  atomic  weights, 
40. 

Elm,  specific  gravity  of,  227. 

Elmore  process  of  electro-depositing 
copper  for  tubes  and  wire  bars, 
331-334. 

Eisner’s  bath  for  tinning,  382. 


Emaille  champ  levee,  307. 
cloisonnee,  306. 
de  fer  contre-oxyde,  303. 
placque-vitro-metallique,  307. 
Emery,  63. 
cloth,  269. 
sticks,  249,  250. 

wheels,  rules  for  the  use  of,  248, 

249. 

which  has  been  used,  to  cleanse, 

250. 

wire,  249. 

Enamel  and  glass,  to  secure  to  metal, 
by  the  electric  current,  307. 
for  cast-iron  articles  as  prepared  in 
England,  300. 

for  cast-iron  pipes,  according  to 
Amtmann,  302. 

for  copper  cooking  utensils,  303. 
for  iron  objects,  299. 
mottled,  301,  302. 
phosphorescent,  307. 
to  test,  for  lead,  75. 
white  for  ornamental  articles,  305. 
Enamels,  colored,  304. 

for  goldsmiths,  304,  305. 

Enamelled  work,  solder  for,  426. 
Enamelling,  engraving,  etching,  decora¬ 
ting,  277-316. 
metals,  298,  299. 

Engine  beams,  contraction  of,  in  cast¬ 
ing,  191. 

England,  brass  wire  from,  99. 
ordnance  bronze  of,  84. 
wire-rod  mill  in,  447. 

English  Britannia  metal,  109. 
bronze  powders,  160. 

German  silver,  112,  113. 
legal  standard  wire  gauge,  446. 
old,  or  London  wire  gauge,  446. 
process  of  pickling  brass,  252,  253. 
silver  soap,  271. 
sterling  metal,  99. 
sterro-metal,  100. 
tombac,  98. 

white  metal  bearings,  89. 
Engravers,  soft  wax  for,  310. 
Engraving,  etching,  enamelling,  deco¬ 
rating,  277-316. 
on  aluminium,  310. 
on  copper,  307,  308. 
on  silver  and  gold,  308-310. 
Engravings,  wood,  metal  suitable  for 
impressions  of,  83. 

Etching,  enamelling,  engraving,  deco¬ 
rating,  277-316. 

Etching  fluid  or  glyphogene  for  steel, 
314. 


INDEX. 


519 


Etching  ground,  310,  311. 

names  on  steel  and  glass,  312,  313. 

on  brass,  311. 

on  copper,  311. 

on  silver,  311. 

on  steel,  311,  312. 

on  zinc,  313. 

solution  for  brass,  313,  314. 
without  etching-ground,  314-316. 
Evans’s  metallic  cement,  240. 

Fahlun  or  tin  brilliants,  118. 

Fastenings  and  rails  per  mile  of  rail¬ 
road,  507. 

Fat  lutes,  397. 

Fenton’s  alloy  for  axle  boxes,  91. 
Ferric  chloride,  45,  46. 
oxide,  255,  256. 
sulphate,  46. 

Ferro-aluminium,  106,  107. 

-manganese,  111. 

Ferrous  chloride,  45. 
sulphate,  45. 
sulphide,  40. 

File,  how  to  tell  a  hand-  from  a 
machine-cut,  77,  78. 

Files  and  other  steel  instruments,  to 
harden,  139. 
metal  for,  88. 

old,  to  make  knives  from,  491. 
polishing,  257. 
to  sharpen,  502-504. 

Fine  wheel,  257. 

Fir,  American,  specific  gravity  of,  227. 
Fire-gilding  and  fire-silvering  iron  and 
steel,  347. 

and  fire-silvering  metals,  which 
cannot  be  amalgamated,  347. 
gilder’s  wax  for,  348,  349. 
silver  objects,  346,  347. 

Fire-proof  and  water-proof  cement,  233. 
Flanges  and  manholes,  Schiefer’s  pack¬ 
ing  rings  for,  239. 

Flasks,  construction  of,  193,  194. 

foundry,  illustrated  and  described, 
196-200. 

Flowers  and  insects,  metallic  coating 
upon,  by  the  galvanic  way,  393. 
Flues,  new  method  of  securing,  504, 
505. 

Fluorine,  symbol  and  atomic  weight  of, 
40. 

Flux,  black,  394,  395. 

Cornish  reducing,  396. 
crude,  396. 
gray,  395. 

Moreau’s  reducing,  396. 
quick,  396. 


Flux  for  reducing  arsenic,  396. 
refining,  396. 
white,  395,  396. 

Fluxes,  394-396. 

and  lutes,  394-397. 

for  arsenical  compounds,  396. 

used  in  soldering,  418. 

Fonte  argentine  or  tinned  cast-iron,  to 
make,  386. 

Forks  and  knives,  bath  for  silvering, 
368. 

and  knives,  cement  to  fasten,  in 
their  handles,  237. 
spoons,  etc.,  metal  for,  114. 

Founders,  blacksmiths  and  locksmiths, 
iron  lacquer  for,  403. 

Founding  and  casting,  189-228. 
of  bells,  207-209. 

Foundry  flasks,  illustrated  and  de¬ 
scribed,  196-200. 

France,  ordnance  bronze  of,  84. 

French  bearing  metal  for  locomotives, 
89. 

bronze,  149,150. 
cast-brass,  100. 

German  silver,  112. 

Fricke’s  German  silver,  113. 

Furnace  for  basic  open  hearth  steel, 
construction  of,  474,  475. 

Furnaces,  lining  for,  495. 

Fusing  points  of  the  principal  metals 
and  other  elements  employed  in 
alloys,  82. 

Galvanic  baths,  temperature  of,  320. 
baths,  water  for,  320. 

Galvanizing,  brassing,  coppering,  gild¬ 
ing,  nickelling,  silvering,  tin¬ 
ning,  electroplating,  etc.,  317- 
394. 

brassing,  coppering, electroplating, 
manufacture,  etc.,  of  wire,  445- 
473. 

of  wire,  465-467. 
old  and  new  parts,  392,  393. 
sheet-iron,  388-392. 
wire,  Roberts’  apparatus  for,  illus¬ 
trated  and  described,  465,  466. 
wire,  Roberts’  apparatus  for  remov¬ 
ing  superfluous  zinc  in,  463, 
467. 

wire,  Vogt’s  arrangement  for  clos¬ 
ing  vessels  in,  466. 
wire,  Wittle’s  and  Kamper’s  ar¬ 
rangements  for  removing  super¬ 
fluous  zinc  in,  466. 

Garden-knives,  bath  used  in  tempering 
and  heating,  144. 


520 


INDEX. 


Garrett’s  wire-rod  mill  near  Chicago, 
447. 

Gas-fixtures  and  chandeliers,  to  cleanse, 
246. 

Gas  retorts,  etc.,  cement  for,  230. 

Gauduin’s  soldering  liquid,  420. 

Gauges,  wire,  460. 

Gedge’s  alloy  for  ship-sheathing,  100. 

German  Britannia  metal,  109. 
clock  bells,  87. 
silver,  alloy  resembling,  108. 
silver,  copper  or  silver,  ungilding 
articles  of,  486. 
silver  for  easting,  113. 
silver,  pickle  for,  319. 
silver,  pickling  of,  253. 
silver,  table  of  composition  of 
various  kinds  of,  112,  113. 
silver,  tombac,  brass  and  copper, 
polishing  of,  268. 
white  metal  bearings,  89. 

German icus,  statue  of,  93. 

Gilders’  wax  for  fire-gilding,  348,  349. 

Gilding  articles  of  metal,  347,  348. 

brassing,  coppering,  galvanizing, 
nickelling,  silvering,  tinning, 
electroplating  etc.,  317-394. 
bronze  for,  94. 
by  adhesion,  346. 

by  contact  and  dipping,  cold  gild¬ 
ing  and  gilding  by  adhesion, 
342-346. 

by  dipping,  baths  for,  344,  345. 
cold,  or  gilding  by  the  rag,  345, 
346. 

imitation,  348. 
improving  bad  tints  of,  347. 
light,  upon  metallic  articles,  to  re¬ 
cognize,  71,  72. 

of  metallic  wire  and  wire  cloth, 
468-470. 

powder  for  copper,  silver,  brass, 
etc.,  348. 
steel,  346. 

to  detect  alloys  in,  74,  75. 
with  a  dead  lustre,  341,  342. 

Gilt  articles,  to  give  a  beautiful,  rich 
appearance  to,  347. 
metallic  articles,  to  detach  gold 
from,  499,  500. 

Girder,  cast-iron,  contraction  of,  in 
casting,  191. 

Girders,  contraction  of,  in  casting,  191. 

Glass  and  brass,  to  unite,  234. 

and  enamel,  to  secure  to  metal,  by 
the  electric  current,  307. 
and  steel,  etching  names  on,  312, 
313. 


Glass  cement,  83. 

cement  for  fastening  brass  to,  236. 
cement  for  fastening  metal  letters 
upon,  235. 

cement  for  fastening  metal  upon, 
235. 

enamel  for  iron,  303. 
lamps,  cement  for  fastening  the 
metal  parts  upon,  234. 
porcelain,  etc.,  metallic  mountings, 
to  fasten  upon,  234. 
powdered,  use  of,  as  a  flux,  418. 
pressed,  alloy  for  moulds  for,  116. 
to  cement  metal  into,  235,  236. 

Glaze  for  iron  pipes,  302,  303. 

or  covering  mass  for  enamelling, 
298,  299. 

Glue  for  pattern-makers,  228. 

Glycerin  cement  for  iron,  233. 
for  sharpening  tools,  504. 

Glyphogene  or  etching  fluid  for  steel, 
314. 

Gold  alloys,  color  of,  100,  101. 

alloys,  table  of  proportion  of  various 
metals  in,  used  by  jewellers, 
101. 

amalgam,  124,  125. 
and  palladium  alloys,  118. 
and  platinum,  preparations  of,  54, 
55. 

and  silver,  alloys  of,  with  copper, 
100-102. 

and  silver,  engraving  on,  308-310. 
and  silver,  new  imitation  of.  120, 
121. 

and  silver,  recovery  of,  from  sweep¬ 
ings,  etc.,  485. 

articles,  polishing  powder  for,  272, 
baths,  338-342. 

baths  for  parts  of  watches,  376. 
baths,  recovery  of  gold  from,  484, 
485. 

beating,  493-495. 
bronze,  95,  148. 
bronze,  genuine,  161. 
bronze  of  great  lustre  on  iron,  154. 
chloride  of,  39,  54. 
color,  metallic,  404. 
coloring  of,  183,  184. 
cyanide  of,  54. 
determination  of,  69. 
fusing  point  of,  82. 
genuine,  solution  of,  in  chlorine 
water.  37. 

hydrocyanate  of,  54. 
lacquers  for,  403. 

-like  alloy,  118. 
mosaic,  99,  161,  162. 


INDEX. 


521 


Gold  or  silver,  damaskeening  with,  281, 

282. 

polishing  of,  268. 
prussiate  of,  54. 

recovery  of,  from  gold  baths,  484, 
485. 

salt,  54,  55. 
solders,  425,  426. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

symbol  and  atomic  weight  of,  40. 
to  detach  from  gilt  metallic  articles, 
499,  500. 

to  distinguish  genuine  from 
spurious,  70,  71. 

to  make  platinum  adhere  to,  429, 
430. 

to  purify  in  the  dry  way,  according 
to  Philipp,  501. 

to  remove  tarnish  from,  after  hard 
soldering,  426. 
tombac  resembling,  98. 
wire,  production  of,  470. 

-workers,  polishing  powder  for, 
272. 

Golden  bronze,  to  cleanse,  245. 

Goldsmiths,  enamels  for,  304,  305. 

Goldware,  fineness  of,  100. 
to  test,  71. 

Gongs,  or  Chinese  tam-tams,  85,  86. 

Gozzy’s  gold  salt,  54,  55. 

Graham’s  bronzing  liquids,  157,  158. 

Graining  of  watch-parts,  373-377. 
powder,  Niiruberg,  374. 

Graphite,  63. 

Gray  flux,  395. 
silver,  102. 

Green  bronze,  149. 

bronze  for  brass,  152,  153. 
bronzing,  153, 154. 
mineral,  48. 
vitriol,  45. 

Grenet’s  battery,  322. 

Grinding,  247-249. 

pickling,  polishing,  cleansing,  241- 
277. 

Groove,  oval,  construction  of  a,  illus¬ 
trated,  448. 

Grooves  of  a  wire-rod  mill,  construction 
of  the,  illustrated,  448. 

Ground  or  ground  mass  for  enamelling, 
298. 

Grouvelle’s  oil  cement,  232. 

Grove’s  battery,  322. 

Gum  elastic,  62,  63. 

Gun-barrels.  Damascus,  illustrated  and 
described,  280,  281. 


Gun-barrels,  damasked,  to  blacken,  188. 
hardening  of,  according  to  Neunert, 
140,  141. 

to  brown,  187,  188. 
to  produce  damask  in  relief  upon, 
282. 

Gun-metal,  contraction  of,  in  casting, 
191. 

mountings,  tombac  for,  98. 

Gun  or  ordnance  metal,  84. 

Guns,  to  cleanse  with  petroleum,  244, 
245. 

Gutta-percha,  63,  64. 

Hadfield’s  manganese  steel,  111,  112. 

Half-round  wire,  illustrated,  453. 

Haloid  salts,  definition  of,  43. 

Hand-saws,  bath  used  in  tempering  and 
heating,  144. 

Hanover,  white  metal  bearings  for  rail¬ 
roads  in,  89. 

Hardening  and  tempering  saws,  482. 
compound,  142. 
of  steel  piano  wire,  473. 
of  wire;  456-459. 

tempering  and  annealing,  126-147. 
water  for  steel,  134. 

Hartshorn,  spirits  of,  61. 

Hatchets,  bath  used  in  tempering  and 
heating,  144. 

Hegermiihle  sheet-brass,  99. 

Henry  IV.,  statue  of,  93. 

Hooks,  etc.,  cement  for  fastening,  230. 

Horn  silver,  53. 

Horse-power,  electrical,  definition  of, 
323. 

Hot  blast-stoves,  blast-pipes,  blowing- 
engines,  etc.,  cement  for,  229. 

House  bells,  87. 

Hoyle’s  alloy  for  pivot  bearings,  91. 

Hulot’s  solder  for  aluminium  bronze, 
424. 

Hydrate,  nickel,  47. 

Hydrochloric  acid,  58,  59. 

acid,  gaseous,  percentage  of,  at 
different  degrees  Be.,  59. 
acid,  use  of  as  a  flux,  418. 

Hydrocyanate  of  gold,  54. 
of  silver,  53. 

Hydrocyanic  acid,  61. 

Hydrogen,  definition  of,  37. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

sulphuretted,  apparatus  for  the 
preparation  of,  44. 
sulphuretted,  precipitates  with,  43- 
45. 


522 


INDEX. 


Hydrogen,  symbol  and  atomic  weight 
of,  40. 

Hydrosulphate  of  ammonia,  62. 

Hyposulphite,  silver,  53,  54. 

Hydroxide,  definition  of  a,  35. 

Imitation  gilding,  348. 
silver  alloys,  102,  103. 

Incrustations,  277,  278. 

India-rubber,  62,  63. 

Indivisible  weights,  definition  of,  41. 

Ink  for  writing  on  tin,  492. 
for  writing  on  zinc,  492. 

Innes,  Max,  varnish  for  metals,  accord¬ 
ing  to,  413. 

Inoxidizing  process  for  cast-iron,  296, 
297. 

process,  Ward’s,  296. 

Insects  and  flowers,  metallic  coating 
upon,  by  the  galvanic  way,  393. 

Instruments,  mechauical,  metal  for, 

SS. 

optical,  to  lacquer,  404-406. 
philosophical,  lacquer  for,  403—404. 

Insulating  coverings  for  steam-pipes, 
etc.,  492,  493. 

mass,  flexible  for  electrical  con¬ 
duits,  493. 

mass  for  steam-boilers,  etc.,  493. 
material  for  electrical  conduits, 
493. 

material  for  steam-pipes,  493. 

Iodine,  symbol  and  atomic  weight  of, 
40. 

Iridium,  symbol  and  atomic  weight  of, 
40. 

Iron  alloy,  118. 
amalgam,  125. 

and  steel  articles,  copper  baths  for, 

329-331. 

and  steel,  Barff ’s  process  for  pre¬ 
serving  from  rust,  297,  298. 
and  steel,  black  varnish  for,  410. 
and  steel,  brush-coppering  for, 
334,  335. 

and  steel,  chemical  change  pro¬ 
duced  in,  by  electric  welding, 
440,  441. 

and  steel,  improvements  in  temper¬ 
ing  and  hardening,  146,  147. 
and  steel,  method  of  ascertaining 
the  quality  of,  75,  76. 
and  steel  objects,  cleansing  of, 
270. 

and  steel,  polishing  of,  268. 
and  steel,  preparation  of,  for  nickel- 
ling,  354. 

and  steel,  sawing  of,  481-483. 


Iron  and  steel,  small  articles  of,  to  blue, 
so  as  to  leave  portions  of  them 
bright,  183. 

and  steel,  tinning  articles  of,  by 
boiling,  381,  382. 
and  steel,  to  color  blue,  182. 
aud  steel,  to  color  gray,  182. 
and  steel,  to  copper,  336. 
and  steel,  to  damaskeen  with  plati¬ 
num,  281. 

and  steel  to  fire-gild  and  fire- 
silver,  347. 

and  steel,  to  nickel  polished  objects 
of,  without  a  battery,  363,  364. 
and  steel,  to  protect  from  rust, 
407. 

and  steel,  ungilding  of,  485,  486. 
and  steel  wire,  coating  which  does 
not  readily  oxidize  upon,  473. 
and  steel  wire,  table  indicating 
size,  weight  and  length  of,  461. 
articles,  cement  for  fastening  in 
stone,  231. 

articles,  desilvering  of,  488. 
articles,  small,  to  blacken  in  bulk, 
180,  181. 

articles,  to  coat  with  copper,  brass 
or  bronze,  336,  337. 
articles,  to  coat  with  other  metals, 
according  to  Newton,  393,  394. 
asphalt  lacquer  on,  401. 
baths,  349-351. 
black,  51,  163. 
black  coating  for,  406,  407. 
brass,  copper,  nickel  bath  for,  358. 
brazing  of,  417. 

brown-black  coating  with  bronze 
lustre  on,  181. 

burnt,  examination  of,  76,  77. 
cast  and  wrought,  and  steel,  ready 
distinction  of,  75. 
cast,  fusing  point  of,  82. 
cast,  inoxidizing  process  for,  296, 
297. 

cast,  malleable,  476—179. 
cast,  to  bronze,  154. 
cast,  to  harden,  131,  132. 
castings,  annealing  of,  126,  127. 
cement  for,  231. 

cement  which  stands  red  heat, 

229. 

cements  or  rust  joints,  228-231. 
chief  difficulty  in  welding,  430. 
combination  of  sulphur  with,  39, 
40. 

combustibility  of,  505,  506. 
connecting  parts  of,  exposed  to 
heat,  cement  for,  230. 


INDEX. 


523 


Iron,  copper  bronze  on,  149. 
glass  enamel  for,  303. 
glycerin  cement  for,  233. 
gold  bronze  of  great  lustre  on,  154. 
how  to  copper,  335,  336. 
improved  method  of  covering  arti¬ 
cles  of,  with  lead,  352,  353. 
in  nickel,  determination  of,  74. 
lacquer  for  blacksmiths,  lock¬ 
smiths,  and  founders,  403. 
lustrous  black  on,  181. 
minium,  46. 
objects,  enamel  for,  299. 
or  steel,  bronze-like  surface  on, 
154,  155. 

painting  of,  408,  409. 
patterns,  to  prevent  rusting  of,  227. 
patterns,  varnish  for,  412,  413. 
plates,  to  cut  out  with  the  assist¬ 
ance  of  sulphuric  acid,  499. 
pots  and  pans,  cement  for  mending, 
231,  232. 

preparations,  45,  46. 
pyrites,  composition  of,  40. 
to  free  from  ingrained  rust,  246. 
rods,  etc.,  cement  tor  fastening,  230. 
sesquioxide  of,  46. 
sheet,  galvanizing  of,  388-392. 
silvering  of,  according  to  Rinmann, 
378. 

soft,  to  harden,  132. 
specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

stoves,  cement  for,  230,  231. 
surfaces,  cement  for  uniting,  229. 
symbol  and  atomic  weight  of,  40. 
testing  for,  68. 
to  cement,  to  iron,  231. 
to  cement,  to  wood  or  stone,  234. 
to  fasten  leather  upon,  236,  237. 
to  fasten  paper  labels  to,  237. 
to  give  a  silver-like  appearance 
with  high  lustre  to,  181,  182. 
to  steel,  or  steel  to  steel,  to  weld, 
433. 

to  zinc  in  the  cold  way,  387,  388. 
Weil’s  process  of  producing  iri¬ 
descent  copper  precipitates  on, 
164,  165. 

wire,  to  copper,  464,  465. 
work,  varnish  for,  412. 
wrought,  fusing  point  of,  82. 
wrought,  ornamenting  of,  by  burn¬ 
ing  on,  205,  206. 

wrought,  to  case-harden,  128-131. 
Iserlohn  sheet  brass,  99. 
tombac,  98. 


Iserlohn,  turned  brass  castings  from,  99. 

Japan,  black,  for  tin  lanterns,  400,  401. 

Japanese  bell  metal,  86. 
bells,  86. 
bronze,  95. 
silver,  102. 

swords,  how  made,  489-491. 

Japanning,  black  grounds  for,  400. 
tin,  397-400. 

vermilion  ground  for,  400. 

Jemappes  sheet  brass,  99. 

Jeweler’s  or  Armenian  cement,  240,  241. 
red,  256. 

table  of  proportion  of  various  metals 
in  gold  alloys  used  by,  101. 

Jewelry,  new  alloy  for  the  manufac¬ 
ture  of,  119,  120. 
tombac  for,  98. 

Joint,  how  to  make  a  permanent  and 
durable,  238,  239. 
wiped,  definition  of  a,  415. 

Joints,  cement  for  filling  in,  229. 
cement  for  making,  232. 
number  of,  per  mile,  of  railroad,  507. 

Kamper’s  &  Wittle’s  arrangement  for  re¬ 
moving  superfluous  zinc  in  gal¬ 
vanizing  wire,  466. 

Karmarsch’s  Britannia  metal,  109. 

Keller’s  Britannia  metal,  109. 

Kettles,  to  tin,  385. 

Klauke  C.,  of  Miincheberg,  near  Ber¬ 
lin,  barbed  wire  manufactured 
by,  454,  455. 

Knife  blades,  sharp  surgical  instru¬ 
ments,  etc.,  nickellingof,  360,  361. 

Knitting  needles,  scouring  and  polish¬ 
ing  of,  243. 

Knives,  to  make,  from  old  files,  491. 
and  forks,  bath  for  silvering,  368. 
and  forks,  cement  to  fasten  in  their 
handles,  237. 

bath  used  in  tempering  and  heat¬ 
ing,  144. 

Labels,  cement  for  fastening  on  polished 
nickel,  237. 

Lace,  to  mould,  in  cast-iron,  200,  201. 

Lacquer,  asphalt,  on  iron,  401. 
for  steel,  404. 
for  tinfoil,  404. 

gold  colored,  for  brass  watch  cases, 
402. 

gold,  for  metallic  articles,  402. 
gold,  for  tin-plate,  402. 
green,  403. 

Lacquering  brass,  401,  402. 


524 


INDEX. 


Lacquering  optical  instruments,  404- 
406. 

Lacquers  for  brass,  402. 
for  gold,  403. 

for  philosophical  instruments,  403, 
404. 

paints  and  varnishes,  397-413. 

Lamps,  petroleum,  bismuth  cement  for 
cementing  the  glass  parts  on,  240. 

Lancets,  bath  used  in  tempering  and 
heating,  144. 

Laps, illustrated  and  described,  480,  481. 

Larch,  specific  gravity  of,  227. 

Laws  of  combination  of  the  elements, 
40,  41. 

Lead,  acetate  of,  42,  49, 

and  antimony  alloys,  polishing  of, 

269. 

baths,  351. 

black,  63. 

carbonate,  49. 

chloride,  39,  49,  50. 

chloride,  dry,  soldering  with,  425. 

chromate,  50. 

contraction  of,  in  casting,  191,  192. 
determination  of,  68,  69. 

-foil,  to  distinguish  tin-foil  from,  73. 
fusing  point  of,  82. 
green  bronze  on,  149. 
improved  method  of  covering  arti¬ 
cles  of  iron  with,  352,  353. 
in  tin,  to  detect,  73. 
lapping,  479-481. 

pipe,  resistance  of,  to  calcium  hy¬ 
drate,  77. 

pipe,  to  cast,  free  from  flaws,  213, 
214. 

pipes,  tinned,  to  prepare,  386. 
pipes,  to  protect,  408. 
plate,  resistance  of,  to  calcium  hy¬ 
drate,  77. 

plates,  to  tin,  385,  386. 
powdered,  solidification  of,  505. 
(Saxonia),  resistance  of,  to  calcium 
hydrate,  77. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

sugar  of,  42,  49. 
sulphate,  50. 

symbol  and  atomic  weight  of,  40. 
tin  and  bismuth,  preparations  of, 
49,  50. 

to  coat  metals  with,  351,  352. 
to  give  to,  the  capacity  of  firmly 
adhering  to  other  metals  and  to 
amalgamate  with  them,  500. 
to  separate  from  zinc,  4S9. 


Lead,  to  test  enamel  for,  75. 
white,  49. 

Leading,  hot,  alloys  for,  354. 

Leyson’s  process  of,  353,  354. 
Leather,  dirty  polishing,  to  cleanse,  276, 
277. 

to  fasten  upon  iron,  236,  237. 
Lechesne,  108. 

Lemarquand’s  non-oxidizable  alloy, 
119. 

Leyson’s  process  of  leading,  353,  354. 
Lightning  rods,  metal  roofs,  etc.,  to  pro¬ 
tect  from  rust,  407,  408. 

Lime  for  polishing,  255. 

tree  wood,  specific  gravity  of,  227. 
Lining  for  furnaces,  495. 

Lipowitz’s  alloy,  83. 

metal,  amalgam  of,  123. 

Litmus  paper,  preparation  of,  42. 

tincture,  preparation  of,  42. 

Little’s  speculum  metal,  97. 

Liver  of  sulphur,  preparation  of,  292. 
Loam,  Windsor,  397. 

Locksmiths,  blacksmiths,  and  founders, 
iron  lacquer  for,  403. 

Locomotive  axles,  bearings  for,  88. 
brass  castings,  89,  90. 
cylinders,  contraction  of,  in  casting, 
191. 

Locomotives,  bearing  metals  for,  89. 
Dewrance’s  patent  bearing  for,  91. 
Fenton’s  alloy  for  axle-boxes  of,  91. 
London  or  old  English  wire  gauge,  460. 
Louis  XIV.,  Keller’s  statue  of,  93. 
Lubricant  for  wire-drawing,  recom¬ 
mended  by  Chas.  H.  Morgan,  451. 
Lubricants  used  in  wire-drawing,  450, 
__  451. 

Lubricator,  oil  of  mustard  as  a,  495. 
Lucerne,  ordnance  bronze  of,  84. 
Liidenscheid,  brass  from,  99. 

sheet  brass,  99. 

Lunar  caustic,  52,  53. 

Lustre,  metallic,  alteration  in,  34. 
Lutecine  or  Paris  metal,  119. 

Lutes,  396,  397. 

and  flaxes,  394-397. 
fat,  397. 

Machine  bronze,  87-92. 

Machines,  cements  for  parts  of,  237,  238. 
rapidly  running,  approved  compo¬ 
sitions  for  bearings  of,  89. 
wrought-iron  parts  of,  to  harden, 
132,  133. 

Magnesia  (calcinedl,  64. 
formation  of,  35. 

Magnesium,  determination  of,  67. 


INDEX. 


525 


Magnesium  monoxide,  formation  of,  35. 

symbol  and  atomic  weight  of,  40. 
Magnets,  to  temper,  148. 

Mahogany,  Honduras,  specific  gravity 
of,  227. 

Malleable  brass,  119. 

Britannia  metal,  109. 
bronze,  95,  96. 
cast-iron,  476-479. 

Manganese  alloys,  110-112. 
bronze,  sheet  from,  100. 
silver,  111. 
steel,  111,  112. 

symbol  and  atomic  weight  of,  40. 
testing  for,  6S. 

Manholes  and  flanges,  Schiefer’s  pack¬ 
ing  rings  for,  239. 

Mannheim  gold,  98. 

Maple,  specific  gravity  of,  227. 

Marble,  cement  for  fastening  metal  let¬ 
ters  upon,  235. 

Marley’s  non-oxidizable  alloy,  119. 
Marsh’s  apparatus  illustrated  and  de¬ 
scribed,  70. 

Marteaux  and  Robert’s  cement,  233. 
Mastic,  Serbat’s,  232,  233. 

Matrix  mass  for  the  reproduction  of 
medals,  coins,  etc.,  495. 

Medals  and  coins,  to  brown,  188,  189. 
cleansing  of,  245. 

metal  suitable  for  impressions  of, 
83. 

to  bronze,  156, 157. 

Medium  wheel,  257. 

Meidinger’s  battery,  322. 

Mercuric  chloride,  52. 
nitrate,  52. 

Mercurous  nitrate,  52. 
sulphate,  52. 

Mercury  and  silver,  preparations  of, 
52-54. 

determination  of,  67,  68,  69. 
fusing  point  of,  82. 
symbol  and  atomic  weight  of,  40. 
Metal,  Aich’s,  99. 
albata,  114. 

apparatus  for  casting,  illustrated 
and  described,  224,  225. 
Ashberry,  109,  110. 

Babbitt’s  anti-attrition,  90,  91. 
Biddery,  109,  110. 

British  plate,  114. 
cliche,  83. 

for  spoons,  forks,  etc.,  114. 
gun  or  ordnance,  84. 
industry,  the  most  important  me¬ 
tallic  preparations  and  the  chemi¬ 
cals  used  in  the,  45-66. 


Metal  industry,  various  chemicals  and 
substances  used  in  the,  61-66. 
-leaf,  combustion  of  in  chlorine,  37. 
letters  upon  glass,  marble,  wood, 
etc.,  cements  for  fastening,  235. 
method  for  producing  drawings  in 
relief  upon,  316. 
minofor,  110. 

Newton’s,  83. 

parts  upon  glass  lamps,  cement  for 
fastening,  234. 

photo-cheuiical  process  of  decorat¬ 
ing,  294,  295. 

pipes,  manufacture  of,  491. 
plates,  to  cement  onto  wooden 
boxes,  234. 

preparation  of  chills  for  casting,  225. 
Prince’s,  99. 

readily  fluid,  suitable  for  impres¬ 
sions  of  plaster  of  Paris  moulds, 
etc.,  83. 

Robierre’s,  100. 

roofs,  lightning  rods,  etc.,  to  pro¬ 
tect  from  rust,  407,  408. 

Rose’s,  83. 

-sheets,  thin,  to  cement,  234. 
to  cement  glass  into,  235,  236. 
to  gild  articles  of,  347,  348. 
to  secure  enamel  and  glass  to,  by 
the  electric  current,  307. 
upon  glass,  cement  for  fastening, 
235. 

Warne’s,  102. 
white,  87,  111. 
white,  definition  of,  83. 

Metallic  articles,  gilt,  to  detach  gold 
from,  499,  500. 

articles,  gold-colored  coating  upon, 
166,  167. 

articles,  gold  lacquer  for,  402. 
articles,  to  recognize  light  gilding 
upon,  71,  72. 

coating  upon  flowers  and  insects  by 
the  galvanic  way,  393. 
cement,  83. 
cement,  Evans’s,  240. 
chlorides,  definition  of,  37. 
chlorides,  preparation  of,  illus¬ 
trated  and  described,  37,  38. 
gold  color,  404. 

mountings,  to  fasten  upon  glass, 
porcelain,  etc.,  234. 
objects,  dipping  or  pickling  of, 
250-254. 

preparations,  the  most  important, 
and  the  chemicals  used  in  the 
metal  industry,  45-66. 
salts,  41-43. 


526 


INDEX. 


Metallic  wire  and  wire  cloth,  to  gild, 
468-470. 

Metallochromy,  163,  164. 

Metallography,  316. 

Metals  and  alloys,  resistance  of,  to 
calcium  hydrate,  77. 
approved  coatings  for,  165,  166. 
base,  36. 

beautiful  steel  gray  for,  166. 
behavior  of,  towards  oxygen,  34- 
36. 

black  coat  for,  165,  166. 
black  or  colored  coat  for,  165. 
changes  iu,  in  alloying,  79. 
chemical  relations  of,  33-45. 
cleansing  of,  by  means  of  acids 
with  the  use  of  a  galvanic  current, 
242,243. 

cleansing  of,  with  the  sand  blast, 
241,  242. 

casting  on  to  other,  204,  205. 
coins,  etc.,  matrix  mass  for  the 
reproduction  of,  495. 
colored  coatings  for,  167,  168. 
combinations  of,  with  chlorine,  36- 
39. 

combinations  of,  with  sulphur, 
39,  40. 

combustion  of,  35. 

contraction  of  in  casting,  191,  192. 

definition  of,  33. 

directions  for  the  determination  of 
impurities  of  the  most  important, 
66-78. 

drawing  properties  of,  445. 
enamelling  of,  298,  299. 
for  bearings,  88,  89. 
freeing  of,  from  grease,  318. 
fusing  point  of  principal,  employed 
in  alloys,  82. 

general  method  of  determining, 
66,  67. 

general  rule  for  fusing,  in  making 
alloys,  81,  82. 

goldeu-yellow  to  brown  coat  for, 
165. 

green  varnish  for,  412. 
how  to  prepare  a  rough  surface  in 
grounding,  for  subsequent  decora¬ 
tion,  295,  296. 

improved  process  of  tinning,  384, 

385. 

iridescent  colors  upon,  283. 

methods  of  bronzing,  148. 

new  method  of  decorating,  287, 

288. 

new  protecting  coat  on,  294. 
noble,  36. 


Metals,  phenomena  in  the  treatment  of 
with  acids,  42. 

polishing  of  the  separate,  268, 
269. 

powdered,  solidification  of,  505. 
preliminary  conditions,  necessary 
for  the  electro-deposition  of,  317, 
318. 

rouge  for  polishing,  274,  275. 
shrinking  of,  in  casting,  189-192. 
soft  alloy  for  coating,  122,  123. 
soft,  polishing  agent  for,  270. 
solution  of,  66. 

speed  of  saws  for  cutting,  482. 
spinning  of,  illustrated  and  de¬ 
scribed,  495-499. 

terms  used  iu  the  electrolytic  depo¬ 
sition  of,  323. 

to  be  nickelled,  preparation  of, 
354-356. 

to  coat  iron  articles  with  other, 
according  to  Newton,  393,  394. 
to  coat  with  lead,  351,  352. 
to  coat  with  platinum  in  a  cheap 
way,  367,  368. 
to  fasten  on  wood,  234,  235. 
to  give  to,  the  capacity  of  firmly 
adhering  to  other  metals,  and  to 
amalgamate  with  them,  500. 
to  polish,  254,  255. 
to  prevent  from  rusting,  500. 
used  by  the  metal  worker,  33. 
varnish  for,  according  to  Max 
Iunes,  413. 

which  cannot  be  amalgamated,  to 
fire-gild  and  fire-silver,  347. 
white,  testing  of,  74. 

Middleton  W.  B.,  invention  of  weld¬ 
ing  steel  by,  435,  436. 

Mills,  white  metal  bearings  for,  89. 

Minargent,  108. 

Mineral  green,  48. 

Mining  picks,  to  temper,  145. 

Minofor  metal,  110. 

Miscellaneous,  474-507. 

Mitis  castings,  214-217. 

metal,  analyses  of,  215,  216. 

Moen,  machine  for  barhed  wire, patented 
by,  illustrated  and  described, 
455. 

Moire,  colored  on  tin-plate,  285. 
metallique,  283-285. 
on  brass,  285,  286. 

Moreau’s  reducing  flux,  396. 

Morgan,  Chas.  H.,  lubricant  for  wire¬ 
drawing  recommended  by,  451. 

Mosaic  gold,  99,  161, 162. 
gold,  composition  of,  39. 


INDEX. 


527 


Most  important  metallic  preparations, 
and  the  chemicals  used  in  the 
metal  industry,  45-G6. 

Mottled  enamel,  301,  302. 

Moulding  and  moulds,  193-196. 

sand  for  castings  of  ingot  iron,  192. 
sand,  to  prevent  the  baking  of,  192, 
193. 

Moulds  for  pressed  glass,  alloy  for,  1 16. 
plaster  of  Paris,  metal  suitable  for 
impressions  of,  83. 

Mopsset’s  silver  alloy,  102. 

Mudge’s  speculum  metal,  97. 

Muffles  for  articles  to  be  nielled  or 
enamelled,  illustrated  and  de¬ 
scribed,  290,  291. 

Muller’s  soldering  liquid,  419,  420. 
Munich  bronze,  93. 

Muntz  metal,  99. 

Music  plates,  116. 

Musket-barrels,  to  harden  the  bores  of, 
141.. 

Mustard,  oil  of,  as  a  lubricator,  495. 

Napoleon  I.,  statue  of,  93. 

Needles,  to  scour  and  polish,  243,  244. 
Neogen,  108,  109. 

Neunert,  hardening  of  gun-barrels,  ac¬ 
cording  to,  140,  141. 

Neustadt  brass  wire,  99. 

New  alloys,  119,  120. 

imitations  of  gold  and  silver,  120, 
121. 

Newton  and  Ames,  hardening  of  steel, 
according  to,  136. 

Newton’s  metal,  83. 

process  of  coating  iron  articles  with 
other  metals,  393,  394. 

Nickel  alloys,  112-115. 

and  cobalt,  preparations  of,  46,  47. 
and  copper  alloys,  112. 
and  steel,  alloys  of,  114,  115. 
bath,  the  most  simple,  356. 
baths,  354-360. 

baths  for  special  purposes,  358,  359. 
baths,  new,  359. 
chloride,  47. 
coins,  112. 

copper  and  zinc  alloys,  112-114. 
determination  of,  67,  68. 
fusing  point  of,  82. 
hydrate,  47. 
nitrate,  47. 

plated  articles,  to  remove  rust  from, 
247. 

Nickel-plating,  regulation  of  current  in, 
359,  360, 

salt,  Adams’,  486. 


Nickel-plating,  to  imitate,  364,365. 

Nickel,  polished,  cement  for  fastening 
labels  on,  237. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

sulphate,  47. 

symbol  and  atomic  weight  of,  40. 
testing  of,  74. 

to  recover  from  old  solutions,  486, 
487. 

various  colors  upon,  170. 
waste,  utilization  of,  486. 
watch  movements,  to  freshen  up, 
247. 

Nickelling,  brassing,  coppering,  gal¬ 
vanizing,  gilding,  silvering,  tin¬ 
ning,  electro-plating,  etc.,  317- 
394. 

cheap  articles,  baths  for,  357,  358. 
composition  of  the  baths  for,  356. 
of  knife  blades,  sharp  surgical  in¬ 
struments,  etc.,  360,  361. 
of  wire,  470,  471. 

phenomena,  which  may  occur  in, 
and  means  of  avoiding  them, 
361-363. 

polished  objects  of  steel  and  iron 
without  a  battery,  363,  364. 
solution,  Pott’s,  356,  357. 
solution,  Weston’s,  356. 
solutions,  Powell’s,  357. 
to  improve  defective,  363. 

Nicking  saws,  manufacture  of,  481,  482. 

Niel,  composition  and  preparation  of, 
288  289 

Nielled  silver,  288-291. 

work,  to  imitate  by  the  galvanic 
method,  292. 

Niello,  Corvin’s,  278,  279. 

Nitrate,  bismuth,  50. 
cobaltous,  47. 
copper,  48. 
mercuric,  52. 
mercurous,  52. 
nickel,  47. 
of  silver,  52,  53. 

Nitric  acid,  57,  58. 

acid,  anhydrous,  percentage  of,  at 
different  degress  Be.,  58. 

Nitrogen,  svmbol  and  atomic  weight  of, 
40. 

Nitro-muriatic  acid,  59,  60. 

Non-magnetic  alloys  for  watches,  121. 

Non-oxidizable  alloy,  122. 

Niirnberg  gold,  109. 

graining  powder,  374. 
tombac,  98. 


528 


INDEX. 


Ocker  cast  brass,  99. 
sheet  brass,  99. 
tombac,  98. 

Ohms,  definition  of,  323. 

Oil  cement,  Grouvelle’s,  232. 
cement,  Stephenson’s,  232. 
of  mustard  as  a  lubricator,  495. 
of  vitriol,  56,  57. 

Olszewskv’s  and  de  Bernados’  method 
of  electric  welding,  illustrated  and 
described,  440-444. 

Optical  instruments,  to  lacquer,  404- 
406. 

Ordnance  bronze,  composition  of,  of 
various  times  aud  countries,  84. 
or  gun-metal,  84. 

Ormolu,  96. 

Oroide,  98. 

Otto’s  speculum  metal,  97. 

Oven-doors,  cement  for,  239. 

Oxalic  acid,  61. 

Oxidation,  definition  of,  35. 

Oxide,  argentic,  53. 
cobaltous,  47. 

cupric  and  cuprous  formation  of,  35. 
ferric,  255,  256. 
zinc,  51. 

Oxides,  cupric  and  cuprous,  49. 
Oxidized  silver,  292-294. 

Oxygen,  behavior  of  metals  towards, 
34-36. 

symbol  and  atomic  weight  of,  40. 
Oxyhydrogen,  definition  of,  37. 

Paint  for  preserving  ^inc  roofs,  410. 
for  sheet-iron  roofs,  409,  410. 
for  wheel  patterns,  226. 

Paints,  Lacquers,  and  Varnishes,  397- 
413. 

Painting  of  iron,  408,  409. 

Palladium  and  gold  alloys, -118. 

symbol  and  atomic  weight  of,  40. 
Pans  and  pots,  iron,  cement  for  mend¬ 
ing,  231,  232. 

Paper  labels,  to  fasten  to  iron,  237. 
Paris  clock  bells,  87. 

metal,  or  lutecine,  119. 
mint,  bronzing  in,  151,  152. 
Parisian  polishing  powder,  269. 

Patina,  bronze-like,  upon  tin,  184. 

imitation  of  genuine,  171-173. 
Pattern-makers,  glue  for,  228. 

Patterns,  black-leading  of,  226,  227. 
iron,  to  prevent  from  rusting,  227. 
iron,  varnish  for,  412,  413. 
painting  and  varnishing  of,  225, 226. 
small  alloys  for,  117. 
to  mend,  227,  228. 


Patterns,  varieties  of  wood  most  suitable 
for,  227. 

Pear-tree  wood,  specific  gravity  of,  227. 
Pen  knives,  bath  used  in  tempering 
and  heating,  144. 

Peruvian  bronze,  96. 

Petroleum,  steel,  to  harden  in,  133. 

to  cleanse  guns  with,  244,  245. 
Pewter,  109. 

Philipp’s  method  of  purifying  gold,  501. 
Philosophical  instruments,  lacquers  for, 
'  403,  404.  * 

Phosphate,  ammonium,  61,  62. 
Phosphates,  use  of,  as  fluxes;  418. 
Phosphide  of  copper,  preparation  of,  91. 

of  tin,  preparation  of,  91. 

Phosphor  bronze,  91,  92. 

resistance  of,  to  calcium 
hydrate,  77. 
various  kinds  of,  92. 
Phosphorescent  enamel,  307. 
Phosphoric  acid,  use  of,  as  a  flux,  418. 
Phosphorized  bronze  or  brass  wire,  456. 
Phosphorus,  fusing  point  of,  82. 

symbol  aud  atomic  weight  of,  40. 
Photo-chemical  process  of  decorating 
metal,  294,  295. 

Pickle,  fat,  for  wire-drawing,  451. 
for  a  dead  lustre,  on  brass,  319. 
for  a  dull-grained  surface  on  brass, 
319. 

for  bright  lustre  on  copper  alloys, 
composition  of,  319. 
for  German  silver,  319. 
for  wrought-iron  or  cast-iron  arti¬ 
cles,  250. 

preliminary  for  copper  alloys,  com¬ 
position  of,  319. 

Piano  wire,  steel,  to  harden,  473. 
Pickling  or  dipping  of  metallic  objects, 
250-254. 

polishing,  cleansing,  grinding,  241- 
277. 

Pinchbeck  for  fancy  articles,  98. 

Pine,  American,  specific  gravity  of,  227. 
Pipe-conduits,  not  exposed  to  heat, 
cement  for,  238. 

Pipes,  cast-iron,  enamel  for,  302. 
contraction  of,  in  casting,  191. 
iron,  glaze  for,  302,  303. 
metal,  manufacture  of,  491. 

Piston  packing  rings,  metal  for,  89. 
rings,  metal  for,  88. 

Pistons  and  stuffing  boxes  of  steam- 
engines,  cement  for  packing,  238. 
Pivot  bearings,  Hoyle’s  alloy  for,  91. 
Plaster  of  Paris  moulds,  metal  suitable 
for  impressions  of,  83. 


INDEX. 


529 


Plated  and  silvered  ware,  polishing  of, 
268. 

Plates,  manner  of  electrically  welding, 
444. 

Platinic  chloride,  55. 

Platinizing  by  the  wet  method,  366, 
367. 

copper,  366. 

Platinoid,  122. 

Platinum,  ammonio-chloride  of,  55. 
and  gold,  preparations  of,  54,  55. 
Birmingham,  117. 
baths,  365,  366. 
bronze,  122. 
chloride  of,  39,  55. 
determination  of,  69. 
fusing  point  of,  82. 
recovery  of,  from  platinum  solu¬ 
tions,  488. 

solutions,  recovery  of  platinum 
from,  488. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

spongy,  55. 

symbol  and  atomic  weight  of,  40. 
tetrachloride  of,  55. 
to  coat  metals  in  a  cheap  way  with, 
367,  368. 

to  damaskeen  iron  and  steel  with, 
281. 

to  make  adhere  to  gold,  429,  430. 
welding  of,  436. 

Platoso-ammonium  chloride,  prepara¬ 
tion  of,  365. 

Plough  steel,  446. 

Plumbago,  63. 

Plumbers’  sealed  solder,  420. 

Polishing  agents,  269-274. 

application  of,  257. 
balls  for  silver,  271. 
cartridges  (Putzpatronen),  274. 
cleansing,  grinding,  pickling,  241- 
277. 

files,  257. 

leather,  dirty,  to  cleanse,  276,  277. 
of  the  separate  metals,  268,  269. 
paste  for  brass,  272. 
paste  for  silver,  271. 
pomades  (Putz),  274. 
powder,  Belgian,  270. 
powder  for  gold  articles,  272. 
powder  for  gold-workers,  272. 
powder,  Parisian,  269. 
powders  for  silver,  270,  271. 
rags,  270. 
soaps,  272,  273. 
stock,  257. 

34 


Polishing  water,  273,  274. 

with"  the  burnisher  or  burnishing 
stone,  259  -262. 

Poplar,  white,  specific  gravity  of, 
227. 

Porcelain,  glass,  etc.,  metallic  mount¬ 
ings,  to  fasten  upon,  234. 

Potash,  caustic,  64. 

red  prussiate  of,  46. 
white  prussiate  of,  64. 
yellow  prussiate  of,  46. 

Potassium  bitartrate,  65,  66. 
carbonate,  64. 
cyanide,  64. 
ferroeyanide,  46. 
hydrate,  formation  of,  34. 
hydroxide,  64. 
nitrate,  64. 
oxidation  of,  34. 

sodium  and  calcium  sulphides,  62. 
symbol  and  atomic  weight  of,  40. 
Potin,  99. 

Pots  and  pans,  iron,  cement  for  mend¬ 
ing,  231,  232. 

Potts’  nickelling  solution,  356,  357. 
Powells’  nickelling  solutions,  357. 
Precipitates  with  sulphuretted  hydro¬ 
gen,  43-45. 

Preparations,  copper,  47-49. 
iron,  45,  46. 

of  cobalt  and  nickel,  46,  47. 
of  gold  and  platinum,  54,  55. 
of  lead,  tin  and  bismuth,  49,  50. 
of  mercury  and  silver,  52-54. 
of  zinc,  antimony  and  arsenic,  51, 
52. 

the  most  important  metallic,  and 
the  chemicals  used  in  the  metal 
industry,  45-66. 

Prince’s  metal,  99. 

Protocliloride  of  tiu,  50. 

Protoxide,  definition  of,  35. 

Prussia,  ordnance  bronze  of,  84. 

white  metal  bearings  for  railroads 
in,  89. 

Prussiate  of  gold,  54. 

of  silver,  53. 

Prussic  acid,  61. 

Pump  barrels,  metal  for,  88. 

Pumps  and  pump  chambers,  metal  for, 
89. 

for  the  conveyance  of  milk  of  lime, 
best  metals  for,  77. 

Punches,  metal  for,  88. 

Purple  of  Cassius,  55. 

Putzpatronen,  274. 

Putz  pomades,  274. 

Pyrites,  40. 


530 


INDEX. 


Queen’s  metal,  109. 

Quick  flux,  396. 

Quicksilver  water,  349. 

Railroad  car  axles,  bearings  for, 

88. 

rails  and  fastenings  per  mile  of, 
507. 

Railroads,  white  metal  bearings  for, 

89. 

Rails  and  fastenings  per  mile  of  rail¬ 
road,  507. 

old  steel,  to  make  new,  435,  436. 

Ramsden’s  method  of  hardening  wire, 
illustrated  and  described,  456- 
459. 

Razors,  bath  used  in  tempering  and 
heating,  144. 

Recovery  of  copper,  483,  484. 

of  gold  and  silver  from  sweepings, 
etc.,  485. 

of  gold  from  gold  baths,  484, 
485. 

of  platinum  from  platinum  solu¬ 
tions,  488, 

of  silver  from  old  cyanide  plating 
solutions,  487. 

Red-brass,  87,  111. 

and  similar  alloys,  table  of  com¬ 
position  of,  98. 
bearings,  88. 

turnings,  utilization  of,  483. 

Red  bronze,  149. 

prussiate  of  potash,  46. 

Refining  flux,  396. 

Reichenhall,  alarm-bell  at,  86. 

Resist,  composition  of,  375. 

Richardson’s  speculum  metal,  97. 

Riley,  Edward,  analyses  of  mitis  metal 
by,  215,  216. 

Rinmann,  silvering  of  iron,  according 
to,  378. 

Ripping  blocks,  452. 

Robb,  J.,  hardeniug  mixture,  patented 
by,  135. 

Robert’s  and  Marteaux’s  cement,  233. 

Roberts’  apparatus  for  removing  super¬ 
fluous  zinc  in  galvanizing  wire, 
466,  467. 

apparatus  for  galvanizing  wire, 
illustrated  and  described,  465, 
466. 

Robierre’s  metal,  100. 

Rockline’s  method  of  bronzing,  159. 

Roebling’s,  John  A.,  Sons  Co.,  of  Tren¬ 
ton,  N.  J.,  tables  relating  to  wire, 
by,  459-463. 

wire  gauge,  460. 


Roll  of  a  wire-rod  mill,  construction  of 
the  grooves  of  a,  448. 

Roman  speculum  metal,  97. 

Roofs,  sheet-iron,  paint  for,  409,  410. 

zinc,  paint  for  preserving,  410. 
Rose’s  metal,  83. 

Rosthorn’s  sterro-metal,  100. 

Rouen,  alarm-bell  at,  86. 

Rouge,  46,  256. 

for  polishing  metals,  274,  275. 
Roughing  wheel,  257. 

Rubber,  vulcanized,  63. 

India,  62,  63. 

Russia,  ordnance  bronze  of,  84. 

Rust,  Barff’s  process  for  preserving  iron 
and  steel  from,  297,  298. 
ingrained,  to  free  iron  from,  246. 
new  preventive,  407. 
to  extract  from  steel,  246,  247. 
to  protect  iron  and  steel  from, 
407. 

to  protect  lightning-rods  and  metal 
roofs  from,  407,  408. 
to  remove  from  nickel-plated 
articles,  247. 

to  remove  from  polished  steel  arti¬ 
cles,  246. 

joints  or  iron  cements,  228-231. 
Rusting  in  of  screws,  to  prevent,  500. 
to  keep  steel  from,  500. 
to  prevent  iron  patterns  from,  227. 
to  prevent  metals  from,  500. 

Sal  ammoniac,  use  of,  as  a  flux,  418. 

auri  Figuieri,  54,  55. 

Sallit’s  speculum  metal,  97. 

Salt  cake,  396. 

of  sorrel,  61. 

Saltpetre,  64. 

Salts,  definition  and  characteristics  of, 
42. 

haloid,  definition  of,  43. 
insoluble  in  water,  43. 
metallic,  41—43. 

Sand  blast,  cleansing  metals  with  the, 
241,  242. 

blast,  illustrated  and  described, 
241,  242. 

blast,  process  of  sharpening  files 
with  the,  503. 

moulding,  for  castings  of  ingot  iron, 
192. 

moulding,  to  prevent  the  baking 
of,  192,  193. 

Savoy,  ordnance  bronze  of,  84- 
Sawing  iron  and  steel,  4S1— 483. 

Saws  and  springs,  to  harden,  137-139. 
hardening  and  tempering  of,  482. 


INDEX. 


531 


Saws,  nicking,  manufacture  of,  481,482. 
small,  bath  used  in  tempering  and 
heating,  144. 

speed  of,  for  cutting  metals,  482. 
to  solder,  428,  429. 

Scalpels,  bath  used  in  tempering  and 
heating,  144. 

Schaefer’s,  Adam,  fluid  for  hardening 
steel,  141. 

packing  rings  for  manholes  and 
flanges,  239. 

Schniewindt’s  apparatus  for  half-round 
wire,  illustrated,  453. 

Schweinfurt  green,  52. 

Scratch-brush  lathe,  illustrated  and  de¬ 
scribed,  266,  267. 

Scratch-brushes,  circular,  illustrated 
aud  described,  266,  267. 

-brushes,  hand,  illustrated  and  de¬ 
scribed,  263-265. 

-brushing,  263-268. 

Screws,  casting  brass  nuts  ou,  203,  204. 
rusted,  to  loosen,  500. 
small,  to  clean,  246. 
to  prevent  rusting  in  of,  500. 

Selenium,  symbol  and  atomic  weight 
of,  40. 

Serbat’s  mastic,  232,  233. 

Sesquioxide  of  iron,  46. 

Shakdo,  122. 

Sheet  and  wire,  brass  for,  97. 

-brass,  to  cut  by  chemical  means, 
499. 

-brass,  to  roughen  for  painting, 
499. 

for  pressed  articles,  metal  for,  88. 
-iron,  galvanizing  of,  388-392. 

-iron  roofs,  paint  for,  409,  410. 
metal,  colored  varnish  for,  411, 
412. 

metals,  bright  asphalt  varnish  for, 
411. 

Sheffield  German  silver,  113. 

Shepherd,  statue  of,  93. 

Ship  sheathing,  metals  for,  99,  100. 

Shoder,  494. 

Shovels,  metal  for,  88. 

Shrinking  of  metals  in  casting,  ISO- 
192. 

Sideraphtite,  122. 

Side  rods,  brasses  for,  89. 

Silicon  brass,  92. 
bronze,  92. 

Silicium,  symbol  and  atomic  weight  of, 
40. 

Silver  alloy,  Mousset’s,  102. 
alloy  resembling,  102,  108. 
amalgam,  125. 


Silver  aud  gold,  alloys  of,  with  copper, 
100-102. 

and  gold,  engraving  on,  308-310. 
and  gold,  new  imitations  of,  120, 
121. 

and  gold,  recovery  of,  from  sweep¬ 
ings,  etc.,  4S5. 

and  mercury,  preparations  of,  52- 
54. 

aud  plated  ware,  polishing  of,  268. 
baths,  368-370. 
bell  metal,  87. 
bronze,  148,  149. 
bronze  powder,  genuine,  162. 
bronze  powder,  imitation,  162. 
carbonate,  53, 
chloride  of,  39,  53. 
cleansing  articles  of.  245. 
copper,  brass,  etc.,  gildiDg  powder 
for,  348. 

copper  or  German  silver,  ungilding 
articles  of,  486. 
cyanide  of,  53. 
determination  of,  69. 
dipping  of,  319. 
etching  on,  311. 
fusing  point  of,  82. 

German,  table  of  composition  of 
various  kinds  of,  112,  113. 
granulated,  mode  of  making,  487. 
gray,  102. 

hydrocyanate  of,  53. 
hyposulphite,  53,  54. 
imitation  alloys  of,  102,  103. 
Japanese,  102. 
manganese,  111. 
milled,  288-291. 
nitrate,  52,  53. 
objects,  to  fire-gild,  346,  347. 
or  gold,  damaskeening  with,  281, 
282. 

oxidized,  292-294. 
polishing  balls  for,  271. 
polishing  of,  268. 
polishing  paste  for,  271. 
polishing  powders  for,  270,  271. 
prussiate  of,  53. 

recovery  of,  from  old  cyanide  plat¬ 
ing  solutions,  487. 
soap,  English,  271. 
soap,  rose-color,  271. 
solders,  426,  427. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

sulphate,  53. 
sulphide,  53. 

symbol  and  atomic  weight  of,  40. 


532 


INDEX. 


Silver,  test-water  for,  72,  73. 
to  burnish,  263. 

-ware,  cleansing  of,  270. 

-ware,  fineness  of,  100. 

-ware,  gilded,  ungilding  of,  485, 
486. 

white  alloy  closely  resembling, 
103. 

Silvering,  alloy  for,  379,  380. 

Bessemer  steel  and  utensils  of  it, 
378,  379. 

Birmingham,  377,  378. 
brassing,  coppering,  galvanizing, 
gilding,  nickelling,  tinning, 
electro-plating,  etc.,  317-394. 
by  contact,  370,  371. 
by  dipping,  371. 
cold,  372,  373. 
light,  to  recognize,  72. 
mechanical,  according  to  Bertrand, 
378. 

of  iron,  according  to  Kinmann, 
378. 

Silveroid,  96. 

Similor,  98. 

Sleigh  bells,  table  bells,  clock  bells, 
etc.,  86,  87. 

Smee’s  battery,  322. 

Soap,  English  silver,  271. 

Soaps,  polishing,  272,  273. 

Soda,  bibasic  phosphate  of,  65. 
caustic,  64. 

tribasic  phosphate  of,  64,  65. 
Sodium  biborate,  62. 
bicarbonate,  64. 
hydroxide,  64. 
phosphate,  64,  65. 
potassium  and  calcium  sulphides, 
62. 

pyrophosphate,  65. 
symbol  and  atomic  weight  of,  40. 
Soft  solder,  83. 

Solder,  bismuth,  421. 

for  enamelled  work,  426. 
for  girdlers,  422. 
half-white,  readily  fusible,  422. 
hard,  according  to  Volk,  422. 
malleable,  422. 
readily  fusible,  422. 
refractory,  422. 
silver,  426,  427. 
soft,  83. 

soft,  for  aluminium  bronze,  424. 
soft,  to  color.  429. 
very  ductile,  422. 
very  refractory,  422. 
white,  422. 

Soldering  and  solders,  413-430. 


Soldering  cast-iron,  424,  425. 
cast-iron  objects,  425. 
cold,  alloy  for,  427,  428. 
copper  wire,  428. 
fat,  419. 

iron,  preparation  of,  414,  415. 

liquid,  Gauduin’s,  420. 

liquid,  Miller’s,  419,  420. 

liquid,  new,  420. 

liquid,  preparation  of,  418,  419. 

of  aluminium  bronze,  423,  424. 

paste,  419. 

saws,  428,  429. 

with  dry  lead  chloride,  425. 

without  a  soldering  iron,  429. 

Solders  and  soldering,  413-430. 
argentan,  424. 
for  aluminium,  423. 
for  aluminium  bronze  jewelry,  424. 
gold,  425,  426. 
hard,  421,  422. 
hard,  definition  of,  413. 
hard,  tables  showing  the  composi¬ 
tion  of,  422. 
soft,  definition  of,  413. 
soft,  preparation  of,  421. 
soft,  table  showing  the  composition 
of,  420. 

soft,  testing  of,  73. 

Sorrel,  salt  of,  61. 

Speculum  metal,  96,  97. 

metal,  standard  alloy,  97. 

Spelter,  417. 

solder,  421,  422. 

Spence’s  metal,  65. 

Spikes,  number  of,  per  mile  of  railroad, 
507. 

Spinning  of  metals,  illustrated  and  de¬ 
scribed,  495-499. 
tools,  illustrated,  496,  497. 

Spirits  of  hartshorn,  61. 

Splices,  number  of,  per  mile  of  rail¬ 
road,  507. 

Spoons,  alloy  for,  102. 

forks,  etc.,  metal  for,  114. 

Spring  steel,  coating  for  bars  of,  not 
acted  upon  by  acids,  alkalies, 
etc.,  406. 

Springs  and  saws,  to  harden,  137-139. 
large,  bath  used  in  tempering  and 
heating,  144. 

Stain,  deep  black  blue,  on  brass,  178. 

Stains,  gold  and  orange,  for  brass, 
179. 

Stamps,  book  binders’,  cast  brass  for, 

99. 

Stannic  sulphide,  50. 

Stannous  chloride,  50. 


INDEX. 


533 


Statuary  bronze,  92-94. 

bronze,  table  of  colors  of  alloys  for, 
93. 

Statues,  best  bronze  for,  94. 

table  of  the  composition  of  a  few 
celebrated,  93. 

Steam  boilers,  etc.,  insulating  mass  for, 
493. 

-engines,  cement  for  packing,  stuff¬ 
ing  boxes  and  pistons  of,  238. 
-pipes,  cement  for,  238. 

-pipes,  insulating  material  for,  493. 
-pipes,  etc.,  insulating  coverings 
for,  492,  493. 

-whistles,  metal  for,  88. 

Steel,  Adam  Schaefer’s  fluid  for  hard¬ 
ening,  141. 

agents  for  hardening,  improving 
and  welding,  142,  143. 

American  welding  compound  for, 
433. 

and  glass,  etching  names  on,  312, 
313. 

and  iron  articles,  copper  baths  for, 
329-331. 

and  iron,  BariFs  process  for  pre¬ 
serving  from  rust,  297,  298. 
and  iron,  hlack  varnish  for,  410. 
and  iron,  brush-coppering  for,  334, 
335. 

and  iron,  chemical  change  pro¬ 
duced  in,  by  electric  welding, 
440,  441. 

and  iron,  improvements  in  temper¬ 
ing  and  hardening,  146,  147. 
and  iron,  polishing  of,  268. 
and  iron,  preparation  of,  for  nick- 
elling,  354. 

and  iron,  method  of  ascertaining 
the  quality  of,  75,  76. 
and  iron,  sawing  of,  481-483. 
and  iron,  small  articles  of,  to  blue, 
so  as  to  leave  portions  of  them 
bright,  183. 

and  iron,  tinning  articles  of,  by 
boiling,  381,  382. 
and  iron,  to  color  blue,  182, 
and  iron,  to  color  gray,  182. 
and  iron,  to  copper,  336. 
and  iron,  to  damaskeen  with  pla¬ 
tinum,  281. 

and  iron,  to  fire-gild  and  fire-silver, 
347. 

and  iron,  to  nickel  polished  objects 
of,  without  a  battery,  363,  364. 
and  iron,  to  protect  from  rust, 
407. 

and  iron,  ungilding  of,  485,  486. 


Steel  and  iron  wire,  coating  which  does 
not  readily  oxidize  upon,  473. 
and  iron  wire,  table  indicating  size, 
weight  and  length  of,  461. 
and  nickel,  alloys  of,  114,  115. 
and  wrought-iron,  Thierault’s  proc¬ 
ess  for  coloring,  182,  183. 
articles,  baths  used  in  tempering 
and  heating,  144. 

articles,  fluids  for  hardening,  134, 
135. 

articles,  polished,  to  remove  rust 
from,  246. 

basic  open-hearth,  manufacture  of, 
474,  475. 
baths,  349-351. 

Bessemer,  silvering  of,  378,  379. 
bronze  or  Uchatius  bronze,  85. 
cast-iron  and  wrought-iron,  brass 
bath  for,  327. 

Damascus,  imitation  of,  279,  280. 
effect  of  temperature  on,  144,  145. 
etching  on,  311,  312. 
for  casting,  improved  method  of 
treating,  228. 

for  wire,  amount  of  carbon  permis¬ 
sible  in,  446. 
fusing  point  of,  82. 
general  rule  in  welding,  431. 
glyphogene  or  etching  fluid  for, 
314. 

guns,  damaskeened  surface  upon, 
282,  283. 

hard,  to  make  a  hole  in,  499. 
hardened,  manner  of  cutting,  482, 
483.  _ 

hardening  compound  for,  135. 
hardening  of,  according  to  Newton 
and  Ames,  136. 
hardening  water  for,  134. 
improvement  in  treatment  of,  492. 
instruments  and  files,  to  harden, 
139. 

instruments,  to  harden,  139,  140. 
lacquer  for,  404. 
lustreless  surface  on,  276. 
manganese,  111,  112. 
new  way  of  annealing,  127. 
objects,  to  give  the  appearance  of 
gold  or  good  bronze  to,  155. 
objects,  to  polish,  275,  276. 
or  case-hardened  articles,  tinning 
of,  383,  384. 

or  iron,  bronze-like  surface  on,  154, 
155. 

pens,  Cooper’s  alloy  for,  117. 
piano  wire,  to  harden,  473. 
plates,  thin,  how  to  harden,  135, 136, 


534 


INDEX. 


Steel  rails,  old,  to  make  new,  435,  436. 
sheet,  to  blue  small  articles  of,  183. 
soft,  analysis  of,  475. 
soft,  tensile  strain  of,  475. 
sources  of  danger  in  welding,  431, 
432. 

tempering  colors  of,  143,  144. 
to  avoid  cracks,  curving  and  warp¬ 
ing  in  hardening,  135. 
to  extract  rust  from,  246,  247. 
to  gild,  346. 

to  harden,  by  pressure,  133. 
to  harden  in  petroleum,  133. 
to  harden  in  sealing-wax,  136,  137. 
to  harden  so  that  the  exterior  is 
hard  and  interior  soft,  133,  134. 
to  keep  from  rusting,  500. 
to  make  soft,  so  it  can  be  worked 
like  copper,  127. 
to  polish,  275. 

to  temper  by  electricity,  145. 
tools,  burnt,  to  restore,  502. 
to  weld  iron  or  steel  to,  433. 
two  ways  of  annealing,  127. 
with  steel,  to  unite  by  welding, 
434. 

wrought-iron  and  cast-iron,  ready 
distinction  of,  75. 

Stephenson’s  oil  cement,  232. 
Stereo-plates,  casting  of,  by  the  paper 
process,  217,  218. 

Sterling  metal,  English,  99. 
Sterro-metal  or  Aich  metal,  99. 

metal,  Rosthorn’s,  100. 

Stolba’s  method  of  tinning,  382,  383. 
Stollberg  sheet  brass,  99. 

Stone,  cement  for  fastening  iron  articles 
in,  231. 

or  wood,  iron,  to  cement  to,  234. 
Stourbridge  clay,  397. 

Stoves,  iron,  cement  for,  230,  231. 

tools,  etc.,  to  coat,  296. 

Stubs  or  Birmingham  wire  gauge,  460. 
Stuffing  boxes  and  pistons  of  steam- 
engines,  cement  for  packing,  238. 
boxes,  metal  for,  88. 

Suboxide,  definition  of,  36. 

Substances  and  chemicals,  various, 
used  in  the  metal  industry,  61- 
66. 

Sugar  of  lead,  42,  49. 

Sullage-piece  or  dead-head,  84. 
Sulphate,  ammonio-ferrous,  45. 
cupric,  47,  48. 
cupro-diammonium,  48. 
ferric,  46. 
ferrous,  45. 
lead,  50. 


Sulphate,  mercurous,  52. 
nickel,  47. 
of  copper,  47,  48. 
silver,  53. 
zinc,  51. 

Sulphide,  ammonium,  62. 
cuprous,  formation  of,  39. 
ferrous,  40. 
of  copper,  48. 
of  tin,  formation  of,  39. 
silver,  53. 
stannic,  50. 

Sulphides  of  calcium,  potassium  and 
sodium,  62. 

Sulphur,  65. 

combination  of,  with  iron,  39,  40. 
combinations  of  metals  with,  39, 
40. 

constitution  and  properties  of,  39. 
fusing  point  of,  82. 
liver  of,  preparation  of,  292. 
svmbol  and  atomic  weight  of, 
'40. 

Sulphuretted  hydrogen,  apparatus  for 
the  preparation  of,  illustrated 
and  described,  44. 

precipitates  with,  43-45. 

Sulphuric  acid,  56,  57. 
acid,  fuming,  56. 
acid,  Nordbausen,  56. 
acid,  percentage  of  anhydrous,  at 
different  degrees  Be.,  57. 
acid,  to  cut  out  iron  plates  with  the 
assistance  of,  499. 

Sulphydrate  of  ammonia,  (>2. 

Super-oxides,  definition  of,  35. 

Surgical  instruments,  bath  used 
tempering  and  heating,  144. 
instruments,  knife  blades,  etc., 
nickelling  of,  360,  361. 

Swiss  clock  bells,  87. 

Swords,  bath  used  in  tempering  and 
heating,  144. 

Japanese,  how  made,  489-491. 

Sycamore,  specific  gravity  of,  227. 

Symbols  and  atomic  weights  of  the 
most  important.?  elements,  40. 
how  formed,  41. 

Table  bells,  sleigh  bells,  clock  bells, 

etc.,  86,  87. 

knives,  bath  used  in  tempering  and 
heating,  144. 

for  preparing  aqua  regia,  59. 
of  alloys  exhibiting  greater  density 
than  their  constituents,  80. 
of  alloys  exhibiting  less  density 
than  their  constituents,  80. 


INDEX. 


535 


Table  of  percentage  of  anhydrous  nitric 
acid  at  different  degrees  Be.,  58. 

of  percentage  of  anhydrous  sul¬ 
phuric  acid  at  different  degrees 
Be.,  57. 

of  percentage  of  gaseous  hydro¬ 
chloric  acid  at  different  degrees 
Be.,  59. 

of  the  most  important  elements 
with  their  symbols  and  atomic 
weights,  40. 

Tables  relating  to  wire,  by  John  A. 
Roebling’s  Sons  Co.,  of  Trenton, 
N.  J.,  459-463. 

Talmi  gold,  98. 

Tam  tam,  86. 

Taps  and  dies,  to  temper,  145,  146. 

Tartar,  65,  66. 

emetic,  51. 

Tartaric  acid,  60. 

Telegraph  wire,  92. 

Telephone  wire,  92. 

Tellurium,  fusing  point  of,  82. 

Temperature,  effect  of,  on  steel,  144, 
145. 

of  galvanic  baths,  320. 

Temperatures,  high,  colors  expressing, 
506. 

Tempering  and  hardening  saws,  482. 

colors  of  steel,  143,  144. 

Tempering,  hardening  and  annealing, 
126-147. 

or  “patenting”  of  wires,  452. 

Terra  merita,  403. 

Test-water  for  silver,  72,  73. 

Tetrachloride  of  platinum,  55. 

Thallium,  symbol  and  atomic  weight 
of,  40. 

Thierault’s  process  for  coloring 
wrouglit-iron  and  steel,  182,  183. 

Thompson,  Prof.  Silvanus  P., platinum 
bath  recommended  by,  366. 

Prof.  Elihu,  electric  welding  in¬ 
vented  by,  436. 

Thurston’s  tough,  strong  brass,  99. 

Tiers  argent,  102. 

Ties  for  cotton  bales,  electric  welding 
of,  439. 

Tin  amalgam,  125,  126. 

and  copper,  alloys  of,  83-97. 

and  copper,  contraction  of,  in  cast¬ 
ing,  191. 

and  its  alloys,  sepia-brown  on,  184, 
185. 

articles,  polishing  of,  268,  269. 

baths,  380,  381. 

bismuth  and  lead,  preparations  of, 
49,  50. 


Tin,  bronze-like  patina  upon,  184. 

cast-iron  or  zinc,  to  coat  with  cop¬ 
per,  337. 

contraction  of,  in  casting,  192. 
determination  of,  69. 
dipping  of,  319. 

-foil,  lacquer  for,  404. 

-foil,  to  distinguish  from  lead-foil, 
73. 

fusing  point  of,  82. 
green-bronze  upon,  149. 
ink  for  writing  on,  492. 
japanning  of,  397-400. 
lanterns,  black  japan  for,  400,  401. 
or  Fahlun  brilliants,  118. 
phosphide  of,  preparation  of,  91. 
-plate,  colored  moire  on,  285. 

-plate,  gold  lacquer  for,  402. 

-plate,  to  decorate,  286,  287. 
polishing  agent  for,  270. 
powdered,  solidification  of,  505. 
protocbloride  of,  50. 
pure,  resistance  of,  to  calcium  hy¬ 
drate,  77. 

-putty,  257. 

recovery  of,  from  tin-plate  waste, 
489. 

-salt,  50. 

specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

sulphide  of,  formation  of,  39. 
symbol  and  atomic  weight  of,  40. 
testing  of,  73. 
to  bronze,  155. 
to  detect  lead  in,  73. 
to  give  to,  the  capacity  of  "firmly 
adhering  to  other  metals,  and  to 
amalgamate  with  them,  500. 
Tinned  lead  pipes,  to  prepare,  386. 
Tinning,  brassing,  coppering,  galvaniz¬ 
ing,  gilding,  nickelling,  electro¬ 
plating,  etc.,  317-394. 
by  boiling  articles  of  iron  and 
steel,  381,  382. 
by  contact,  381. 
by  dipping,  381. 
cold,  383. 

Eisner’s  bath  for,  382. 
hard  steel  or  case-hardened  arti¬ 
cles,  383,  384. 
kettles,  385. 
lead  plates,  385,  386. 
metals,  improved  method  of,  384, 
385. 

of  wire  and  wire-gauze,  471-473. 
small  brass  or  copper  objects,  382. 
Stalba’s  method  of,  382,  383. 


536 


INDEX. 


Tires  and  axles,  electric  welding  of,  439. 

Tissier’s  metal,  98. 

Titanium,  symbol  and  atomic  weight 
of,  40.' 

Tombac  and  similar  alloys,  table  of 
composition  of,  9S. 
brass  and  copper,  to  give  a  bril¬ 
liant  appearance  to,  254. 
composition,  characteristics,  and 
properties  of,  97. 

copper,  brass,  and  German  silver, 
polishing  of,  26S. 
dipping  of,  31S. 
pickling  of,  251. 

Tools,  burnishing,  illustrated  and  de¬ 
scribed,  260,  261. 
spinning,  illustrated,  496,  497. 
stoves,  etc.,  to  coat,  296. 
to  harden,  140. 
to  sharpen,  504. 

Tournay’s  metal,  98. 

Trichloride,  antimony,  51. 

Tripoli,  256,  257. 

Tubes  and  wire  bars,  Elmore  process 
of  electro-depositing  copper  for, 
331-334. 

Tucker  bronze,  154. 

Tula  niel,  composition  of,  289. 

Tumbling  drum,  illustrated  and  de¬ 
scribed,  258,  259. 

Tungsten,  symbol  and  atomic  weight 
of,  40. 

Turkey,  ordnance  bronze  of,  84. 

Turkish  damask,  illustrated,  2S0. 

Turpentine,  use  of,  as  a  soldering  agent, 
41S. 

Tutania,  109. 

Type  metal,  table  of  composition  of, 
115,  116. 

Uchatius  bronze  or  steel  bronze,  So. 

Ungilding,  485,  4S6. 

United  States,  composition  of  ordnance 
bronze  in  the,  84. 
method  for  cleaning  brass  parts 
in  the,  253. 

nickel  coins  of  the,  112. 

Uranium,  symbol  and  atomic  weight  of, 
40. 

Ure,  Dr.,  rule  for  calculating  the  specific 
gravity  of  alloys,  by,  SO. 

Utensils,  cast-iron,  to  enamel,  299-301. 

V arious  alloys,  116-123. 

Varnish,  black,  for  iron  and  steel,  410. 
black,  for  zinc,  410,  411. 
bright  asphalt,  for  sheet  metals,  411. 
colored,  for  sheet  metal,  411,  412. 


Varnish  for  bronzing,  148. 
for  common  work,  412. 
for  iron  patterns,  412,  413. 
for  iron  work,  412. 
for  metals,  according  to  Max 
Innes,  413. 

green,  for  metals,  412. 
green  transparent,  412. 

Varnishes,  paints  and  lacquers,  397— 
413. 

Verdigris,  French,  49. 

German,  49. 

Vienna  German  silver,  112. 
lime,  255. 
sheet  brass,  99. 

Vitriol,  blue,  42,  47,  48. 
green,  45. 
oil  of,  56,  57. 
white,  51. 

Vogel,  F.,  fat  pickle  for  wire-drawing 
recommended  by,  451. 

Vogt’s  arrangement  for  closing  vessels 
in  galvanizing  wire,  466. 

Volt,  definition  of,  323. 

Wagner’s  Britannia  metal,  109. 
Wagons,  Fenton’s  alloy  for  axle-boxes 
of,  91. 

Wagon-wheels,  metal  for  boxes  of,  88. 
Walker’s  chemical  bronze,  159. 

Ward’s  inoxidizing  process,  296. 

Ware,  silvered  and  plated,  polishing 

of,  26S. 

Warne’s  metal,  102. 

Waste,  nickel,  utilization  of,  486. 

tin-plate,  recovery  of  tin  from,  4S9. 
Watch  cases,  brass,  gold-colored  lac¬ 
quer  for,  402. 

-dials,  enamelling  of,  306,  307. 
-movements,  nickel  to  freshen  up, 
247. 

-parts,  graining  of,  373-377. 
-springs,  bath  used  in  tempering 
and  heating,  144. 

Watches,  gold  baths  for  parts  of,  376. 

non-magnetic  alloys  for,  121. 
Water  for  galvanic  baths,  320. 

-pipes,  cements  for,  240. 

-proof  and  fire-proof  cement,  233. 
reservoirs,  iron  cement  for  joints 
of,  230. 

Watts,  definition  of,  323. 

Wax-mass  for  copper  engravers,  310. 
soft,  for  engravers,  310. 
to  get  a  copper  deposit  on,  334. 
Webster’s  aluminium  alloys,  107. 
Wedding  on  the  results  of  examina¬ 
tions  of  burnt  iron,  76,  77. 


INDEX. 


537 


Weights,  metal  for,  88. 

Weil’s  process  of  producing  iridescent 
copper  precipitates  on  iron,  164, 
165. 

Welding  and  welding  compounds,  430- 
444. 

cast-steel,  432,  433. 
compound,  American,  for  welding 
steel  to  steel,  433. 
compound  to  weld  steel  to  wrought- 
iron,  433. 

compounds  and  welding,  430- 
444. 

electric,  436-444. 

electric,  apparatus  used  in,  436- 
438. 

electric,  applications  of,  439. 
electric,  process  of,  438,  439. 
electric,  under  water,  441. 
improved  method  of,  434,  435. 
steel  to  wrought  iron,  compound 
for,  433. 

wrought-iron  to  wrought-iron,  com¬ 
pound  for,  433. 

Weston’s  nickelling  solution,  356. 

Westphalische  Union,  of  Hamm, 
barbed  wire  manufactured  by, 
455. 

West,  Thomas  D.,  on  casting  alumini¬ 
um  bronze  and  other  strong 
metals,  211-213. 
eel,  fine,  257. 
medium,  257. 
patterns,  paint  for,  226. 
roughing,  257. 

Wheels,  buff,  257. 

chilled,  manufacture  of,  219-223. 
polishing  by  means  of,  255. 

White  arsenic,  51,  52. 
flux,  395,  396. 
lead,  49. 
metal,  87,  111. 
metal  bearings,  89. 
metal,  definition  of,  83. 
metals,  testing  of,  74. 
prussiate  of  potash,  64. 
table  bells,  87. 
vitriol,  51. 

Willow,  specific  gravity  of,  227. 

Windsor  loam,  397. 

Wiped  joint,  definition  of,  415. 

Wire  and  sheet,  brass  for,  97. 

and  wire-cloth,  metallic,  to  gild. 
468-470. 

and  wire  gauze,  to  tin,  471-473. 
annealing  of,  451,  452. 
barbed,  manufacture  of,  illustrated 
and  described,  453-455. 


Wire,  barbed,  Moen’s  machine  for  the 
manufacture  of,  illustrated  and 
described,  455. 

bars  and  tubes,  Elmore  process  of 
electro-depositing  copper  for,  331- 
334. 

binding,  for  soldering,  414. 
brass,  99. 

brass,  method  of  making,  464. 
cables,. electric  welding  of,  439. 
copper,  weight  per  mile  of,  463. 
copper,  weight  per  1000  feet  of,  462. 
-drawers’  soap  and  grease,  450,  451. 
-drawing  drums,  sizes  of,  452. 
-drawing,  lubricant  for,  recom¬ 
mended  by  Chas.  H.  Morgan,  451. 
-drawing,  lubricants  used  in,  450, 
451. 

-drawing  mill,  essential  features  of 
a,  449,  450. 

-drawing  mill,  illustrated  and  de¬ 
scribed,  450. 

-drawing,  Vogel’s  fat  pickle  for, 
451. 

-drawing,  what  it  consists  in,  445. 
galvanizing,  Vogt’s  arrangement 
for  closing  vessels  in,  466. 
gauges,  460. 

gauze  and  wire,  to  tin,  471-473. 
half-round,  illustrated,  453. 
hardening  of,  456-459. 
iron  and  steel,  table  indicating 
size,  weight,  and  length  of,  461. 
iron,  to  copper,  464,  465. 
manufacture,  brassing,  coppering, 
electro-plating,  galvanizing,  etc., 
of,  445-473. 

mill,  treatment  of  wire-rods  in  the, 
449. 

phosphorized,  bronze  or  brass,  456. 
Ramsden’s  method  of  hardening, 
456^59. 

Roberts’  apparatus  for  galvanizing, 
illustrated  and  described,  465, 466. 
Roberts’  apparatus  for  removing 
superfluous  zinc  in  galvanizing, 
466,  467. 

-rod  mill,  Garrett’s,  near  Chicago, 
447. 

-rod  mill  in  England,  447. 

-rod  roll,  construction  of  grooves 
of  a,  illustrated,  448. 

-rods,  length  of,  finished,  449. 

-rods,  treatment  of,  in  the  wire-mill, 
449. 

steel  and  iron,  coating  which  does 
not  readily  oxidize  upon,  473. 

I  steel  piano,  to  harden,  473. 


INDEX. 


538 


Wire,  tables  relating  to,  by  John  A.  I 
Roebling’s  Sons  Co.,  of  Trenton, 
N.  J.,  459^163. 
telegraph,  92. 
telephone,  92. 

to  brass,  in  the  galvanic  way,  463, 
464. 

to  electro-brass,  464. 
to  galvanize,  465—167. 
to  nickel,  470,  471. 

Wittle’s  and  Kiimper’s  arrangement 
for  removing  superfluous  zinc  in 
galvanizing,  466. 

-work,  continuous  electric  welding 
of,  439. 

Wires,  breaking  strength  of,  447. 
definition  of  qualities  of,  446. 
tempering  or  patenting  of,  452. 
uses  of,  445,  446. 

Wolfram, symbol  and  atomic  weight  of, 
40. 

Wood,  cement  for  fastening  metal  let¬ 
ters  upon,  235. 

engravings,  metal  suitable  for  im¬ 
pressions  of,  83. 

or  stone,  to  cement  iron  to,  234. 
to  fasten  metals  to,  234,  235. 
varieties  of,  most  suitable  for  pat¬ 
terns,  227. 

Woods,  specific  gravity  of,  227. 

Wood’s  alloys,  83. 

W rough t-iron  and  steel,  Thierault’s 
process  for  coloring,  182,  183. 
-iron,  cast-iron  and  steel,  brass  bath 
for,  327. 

-iron  castings,  214-217. 

-iron  or  cast-iron  articles,  pickle 
for,  250. 

-iron,  ornamenting  of,  by  burning 
on,  205,  206. 

-iron  parts  of  machines,  to  harden, 
132,  133. 

-iron,  steel,  and  cast-iron,  ready 
distinction  of,  75. 

-iron,  to  case-harden,  128-131. 

-iron  to  wrought-iron,  compound 
for  welding,  433. 

Yellow  prussiate  of  potash,  46. 

Zach’s  method  for  producing  drawings 
in  relief  upon  metals,  316. 

Ziegenhain,  alarm  bell  at,  86. 

Zinc  amalgam,  126. 

and  copper,  alloys  of,  97-100. 
antimony  and  arsenic,  preparations 
of,  51,  52. 

articles,  copper  bath  for,  330. 


1  Zinc  baths,  386,  387. 

black  varnish  for,  410,  411. 

brass  bath  for,  326,  327. 

bronze-color  on,  186. 

bronzing  liquids  for,  158. 

casting  of,  223,  224. 

castings,  nickel  bath  for,  358. 

chloride  of,  51. 

chloride  of,  formation  of,  38. 

chloride  of,  use  of,  as  a  flux,  418. 

coloring  of,  185-187. 

contraction  of,  in  casting,  191,  192. 

copper  and  nickel  alloys,  112-114. 

copper-bronze  on.  149. 

copper-red  on,  186. 

dipping  of,  319. 

etching  on,  313. 

fusibility  of,  35. 

fusing  point  of,  82. 

gray-coating  on,  1S5,  186. 

green  bronze  on,  149. 

green  coating  on,  186. 

ink  for  writing  on,  492. 

marbling  of,  186. 

ornaments,  colored  cement  for  re¬ 
pairing,  239,  240. 
oxide,  51. 

oxide,  formation  of,  35. 
plates,  to  copper,  337,  338. 
polishing  of,  269. 
powdered,  solidification  of,  505. 
preparation  of,  for  batteries,  324, 
325. 

red-brownish  color  on,  187. 
roofs,  paint  for  preserving,  410. 
specific  gravity  and  chemical  and 
electro-chemical  equivalent  of, 
323. 

sulphate,  51. 

sulphate  and  cupric  sulphate,  brass 
bath  from,  326. 

symbol  and  atomic  weight  of,  40. 
tin  or  cast-iron,  to  coat  with  copper, 
337. 

to  bronze,  155,  156. 
to  give  to,  the  capacity  of  firmly 
adhering  to  other  metals,  and  to 
amalgamate  with  them,  500. 
to  harden,  142. 
to  pickle,  253,  254. 
to  prepare  for  painting,  296. 
to  separate  lead  from,  489. 
wares,  nickel  bath  for,  358. 
white,  51. 

yellow-brown  shades  on,  187. 
Zincking  copper  and  brass  without  a 
battery,  387. 

iron  in  the  cold  way,  387,  388. 


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